Slideshow: The World at Night 2012

Christoph Otawa / The World at Night

Experience the wonders of the night sky in a slideshow that features the winners of the 2012 "Earth & Sky" contest, presented by The World at Night.

Launch slideshow

Light pollution never looked so good: The World at Night's annual photography contest highlights the beauties of the night sky, but it also highlights the challenges posed by humanity's efforts to light up the night.

This year's winners reveal how artificial lighting can add another dimension to the natural wonders of the stars and planets — or spoil the view forever. Hundreds of pictures were sent in from about 50 countries, including exotic locales such as the sub-Antarctic island of South Georgia, the national parks of Reunion Island and the savannas of South Africa, said Babak Tafreshi, the founder and leader of The World at Night. "We received a lot of submissions from Asian countries this year, especially China, India, Iran and Indonesia," the Iranian-born astrophotographer said in an email exchange.

He said the message of The World at Night is definitely getting out: "In general, it looks as if TWAN's aim of reclaiming the natural beauty of the night sky and promoting nightscape photography is reaching a growing audience worldwide, while the activities by amateur and professional astronomers and environmentalists to increase awareness on the light pollution issue is truly getting a lot of public attention."

This year's contest is limited to images taken since the beginning of 2011, but that leaves a lot to choose from — including pictures of Comet Lovejoy, the spectacular "Christmas Comet" that wowed skywatchers in the southern hemisphere, as well as the stunning auroral images that have cropped up over the past few months. Both those phenomena are represented in today's top-10 roundup from TWAN.

Tafreshi drew attention to two potential perils facing astrophotographers nowadays: light pollution and photo fakery. He noted that the increasing glare of city lights was "not just an astronomer's problem," but also "a major waste of energy, and like any other form of pollution, it disrupts ecosystems and has adverse health effects."

"Today, most city skies are virtually empty of stars," he said in his email. "About two-thirds of the human population today lives under light-polluted skies, not dark enough to see the Milky Way. Seeing a real dark sky is a must-see experience in the life of each of us, moments that you will not forget in your entire life."

Tafreshi also said there's a fast-rising concern about images that may not be telling the truth about the earth and sky.

"Unfortunately, a majority of photographers who are interested in nightscape photography are less familiar with astronomy, and the natural look and color of the night sky," he said. "So many landscape astrophotos today are intensely saturated, unnaturally contrasted, and sometimes with totally wrong colors of the sky. We had stunning compositions and amazing landscapes at night, some made by famous photographers, which were ruled out of the contest simply because they were 'overcooked' in processing."

You can rely on TWAN's prize-winning pictures to show the true glories of the night sky, along with the glow of the world below. Check out our slideshow, and read more of Tafreshi's observations in the comment space below.

More astronomy slideshows:

• The World at Night 2011
• Cosmic Log archive of auroral imagery
• All-time top 10 astronomy pictures from APOD
• Month in Space Pictures | Year in Space Pictures 2011

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Is a widely used pesticide to blame for making bees disappear? The debate over a class of chemicals known as neonicotinoids was the focus of a spot on NBC's "Nightly News" tonight, and NBC News' Anne Thompson has supplemented her TV report with a couple of Web-only videos presenting the pro and con arguments on neonicotinoids.

There's little question that pesticides play a role in the malady known as colony collapse disorder, in which whole colonies of honeybees leave their hives abruptly and never return. Most experts would say pesticides are among a host of bee-debilitating factors that also include viruses, mites and fungi. However, in recent months a number of studies have highlighted neonicotinoids as a particularly worrisome threat to bees.

So far, the Environmental Protection Agency has not acknowledged a link between colony collapse disorder and the reported problems with neonicotinoids. The chemicals are attractive to farmers, particularly for corn crops, because they are much more toxic to insects than they are to mammals. The stuff is sprayed on corn seeds as well as plants in the field.

One of the bonus videos is an interview with Steve Ellis, owner of the Old Mill Honey Company in Minnesota. "The quantity of neonicotinoid systemic insecticides that are being used in the country is mind-boggling," he says. Ellis is one of the backers of a petition campaign calling on the EPA to suspend further use of a type of neonicotinoid known as clothianidin.

In the other video, David Fischer, chief ecotoxicologist for Bayer CropScience, contends that neonicotinoids don't kill off bee colonies as long as they're used properly. He contends that in the studies linking the chemicals to colony collapse disorder, the bees were exposed to "unrealistically high levels" of the chemicals. Bayer CropScience markets clothianidin in brand-name pesticides that include Poncho and Prosper.

Watch the three videos, then feel free to weigh in with your vote and/or your comments.

More about the bee debate:

• Two studies link neonicotinoids to bee crash
• Fungal threats are a growing concern
• New bee viruses found attacking healthy hives
• Bees feel the sting of huge population plunge

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Logcommunity by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Bigelow Aerospace

Bigelow Aerospace's Genesis 2 inflatable space module rushes into an orbital sunrise.

SpaceX and Bigelow Aerospace plan to meet with officials in Japan soon after this month's scheduled launch of SpaceX's Falcon 9 rocket and Dragon capsule, to kick off an international marketing effort for private-sector space stations.

The plan, laid out today in a jointly issued news release, calls for clients to go into orbit inside the Dragon and link up with Bigelow's BA 330 inflatable space habitat.

"Together we will provide unique opportunities to entities — whether nations or corporations — wishing to have crewed access to the space environment for extended periods," said SpaceX's president, Gwynne Shotwell. "I'm looking forward to working with Bigelow Aerospace and engaging with international customers."

Robert Bigelow, the billionaire founder and president of Nevada-based Bigelow Aerospace, said he was eager to join up with California-based SpaceX and tell international clients about "the substantial benefits that BA 330 leasing can offer in combination with SpaceX transportation capabilities."

SpaceX is planning to launch an unmanned Dragon cargo capsule into orbit as early as May 19 for a potential test linkup with the International Space Station, and is already working with NASA to modify the Dragon for carrying astronauts as well. Just this week, NASA announced that SpaceX reached a milestone in that development effort by showing that seven astronauts could maneuver effectively inside the Dragon space taxi, even under emergency scenarios.

SpaceX

Astronauts and experts check out the crew accommodations in SpaceX's Dragon spacecraft. On top, from left, are NASA Crew Survival Engineering Team Lead Dustin Gohmert, NASA astronauts Tony Antonelli and Lee Archambault, and SpaceX Mission Operations Engineer Laura Crabtree. On bottom, from left, are SpaceX Thermal Engineer Brenda Hernandez and NASA astronauts Rex Walheim and Tim Kopra.

Bigelow's BA 330 space module would be designed to provide 330 cubic meters of usable volume, which is about the size of a two-bedroom apartment. The BA 330 could accommodate up to six astronauts, depending on how cozy they plan to get. Two or more BA 330 modules could be connected together in orbit for lease by national space agencies, companies or universities, according to Bigelow Aerospace.

Bigelow made his fortune in the hotel industry, which led some to suppose that he was getting into the space-hotel business — but the first users are likely to be researchers or governments aiming to pursue their own space programs on a leased orbital platform. The company has launched two prototype inflatable modules on Russian rockets — Genesis 1 in 2006 and Genesis 2 in 2007 — and both of those unmanned spacecraft are still in orbit.

Mike Gold, who serves as Bigelow Aerospace's director of Washington operations and business growth, told me that the company was ready to move forward with the BA 330 as well as the Bigelow Expandable Activity Module, or BEAM, an upscale version of the Genesis module that could be attached to the International Space Station. Future progress on both those projects is dependent on decisions made by NASA, however. NASA has not yet made a commitment to using the BEAM, and it has not yet announced how it will proceed with the next phase of its effort to support the development of commercial space taxis such as SpaceX's Dragon.

"We'll be ready to proceed when commercial crew is," Gold told me.

SpaceX

An artist's conception shows a SpaceX Dragon spacecraft docked to a Bigelow Aerospace module.

In addition to its marketing arrangement with SpaceX, Bigelow has partnered with the Boeing Co. on a project to create a space taxi called the CST-100 to ferry NASA astronauts. That scenario could see a successor to the CST-100 launched toward a Bigelow-built space station atop United Launch Alliance's Atlas 5 rocket.

Gold said the commercial crew vehicle development program was the "long pole in the tent" for Bigelow Aerospace's plans. Even if Bigelow Aerospace built its BA 330, it would have to rely upon an affordable, reliable, safe system for orbital transport — and that system probably would have to be developed and tested with NASA's help.

Four companies, including Boeing and SpaceX as well as Blue Origin and Sierra Nevada Corp., have been receiving hundreds of millions of dollars in funding from NASA, but it's not yet clear how much money Congress will approve for the next phase of the program. If the funding matches NASA's projected levels, space agency officials have said commercial space taxis could be flying astronauts by 2017. "We hope it could be even earlier," Gold said.

However, it's highly questionable whether NASA will get as much money for commercial crew development as it has requested. The request for fiscal year 2013 was almost $830 million, but a Senate subcommittee cut that figure to $525 million. Today the House passed a bill specifying an even lower funding level, $500 million. The White House has threatened a presidential veto of that bill, in part because of its concerns about the cutback in commercial crew support.

More about SpaceX and Bigelow:

• SpaceX shows off its manned Dragon capsule
• SpaceX plans fully reusable space transports
• Bigelow worries that China will claim the moon
• Inside Bigelow's spaceship factory

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Tyrone Turner / National Geographic

Boston University archaeologist William Saturno carefully uncovers art and writings left by the Maya some 1,200 years ago. The art and other symbols on the walls may have been records kept by a scribe, Saturno theorizes. Saturno's excavation and documentation of the house were supported by the National Geographic Society.

Archaeologists have found a stunning array of 1,200-year-old Maya paintings in a room that appears to have been a workshop for calendar scribes and priests, with numerical markings on the wall that denote intervals of time well beyond the controversial cycle that runs out this December.

For years, prophets of doom have been saying that we're in for an apocalypse on Dec. 21, 2012, because that marks the end of the Maya "Long Count" calendar, which was based on a cycle of 13 intervals known as "baktuns," each lasting 144,000 days. But the researchers behind the latest find, detailed in the journal Science and an upcoming issue of National Geographic, say the writing on the wall runs counter to that bogus belief.

"It's very clear that the 2012 date, this end of 13 baktuns, while important, was turning the page," David Stuart, an expert on Maya hieroglyphs at the University of Texas at Austin, told reporters today. "Baktun 14 was going to be coming, and Baktun 15 and Baktun 16. ... The Maya calendar is going to keep going, and keep going for billions, trillions, octillions of years into the future."

The current focus of the research project, led by Boston University's William Saturno, is a 6-by-6-foot room situated beneath a mound at the Xultun archaeological site in Guatemala's Peten region. Maxwell Chamberlain, a BU student participating in the excavations there, happened to notice a poorly preserved wall protruding from a trench that was previously dug by looters, with the hints of a painting on the plaster.

Saturno said he didn't think there'd be much to the wall, but "I felt we had a responsibility to find out at the very least how large this room was."

When archaeologists worked their way into the mound, they were amazed to find that it was a richly decorated room from the Classic Maya period, dating back to roughly the year 800. One niche was adorned with the faded picture of a Maya king, wearing a blue-feathered headdress and holding a white scepter. The picture of a scribe holding a stylus, perhaps the son or brother of the king, was painted nearby with the label "Younger Brother Obsidian." Another wall showed a row of three stylized black figures, with one bearing the hieroglyphic name "Older Brother Obsidian."

Tyrone Turner / National Geographic

The painted figure of a man — possibly a scribe who once lived in the house built by the ancient Maya — is illuminated through a doorway to the dwelling, in northeastern Guatemala. The structure represents the first Maya house found to contain artwork on its walls. The research is supported by the National Geographic Society.

Tyrone Turner / National Geographic

Never-before-seen artwork — the first to be found on walls of a Maya house — adorn the dwelling in the ruined city of Xultún. The figure at left is one of three men on the house's west wall who are painted in black and wear identical costumes. One of the black figures is named "Older Brother Obsidian." The figure in the center appears to be a scribe, labeled "Younger Brother Obsidian." A Maya king is portrayed at far right. Heather Hurst rendered the paintings in clearer detail below.

Heather Hurst / National Geographic

A vibrant orange figure, kneeling in front of the king on the ruined house's north wall, is labeled "Younger Brother Obsidian," a curious title seldom seen in Maya text. The man is holding a writing instrument, which may indicate he was a scribe. The painting re-creates the design and colors of the figure in the original Maya mural.

Heather Hurst / National Geographic

Three male figures, seated and painted in black, appear in a painting that re-creates the design and colors of a Mural found on the ruined house's west wall. The men wear only white loincloths and medallions around their necks, plus a headdress bearing another medallion and a single feather. One of the figures is particularly burly and is labeled "Older Brother Obsidian." Another is labeled as a youth.

Heather Hurst / National Geographic

A Maya king, seated and wearing an elaborate headdress of blue feathers, adorns the north wall of the ruined house discovered at the Maya site of Xultun. An attendant, at right, leans out from behind the king's headdress. The painting by artist Heather Hurst re-creates the design and colors of the original Maya artwork at the site.

Rows of numbers and hieroglyphs were painted on yet another wall. In fact, it appeared that the wall had been plastered over repeatedly and covered with new sets of figures. "What these are giving us are time spans," Stuart said. "Not so much dates, but Maya notations of elapsed time."

Stuart said some sets of numbers denoted lunar cycles of 177 or 178 days, along with the sign for a patron god that was associated with each cycle. "This was, we think, a calculator for a Maya priest, an astronomer, to figure out lunar ages," he said.

In a news release, Saturno said this represents the first look at "what may be actual records kept by a scribe, whose job was to be official record keeper of a Maya community."

"It's like an episode of TV's 'Big Bang Theory,' a geek math problem and they're painting it on the wall," Saturno said. "They seem to be using it like a blackboard."

In addition to lunar cycles, the calculations on the wall could relate to the periods of Venus, Mercury and Mars, the researchers reported. Stuart said such calculations could have come into play for predicting eclipses. He imagined that there might be "one or more, maybe two or three of these astronomers or calendar priests working, sitting there on a workbench and writing these notations on the wall."

One array of numbers would be particularly intriguing to doomsday debunkers: lists that appear to denote wide ranges of accumulated time, including a 17-baktun period. "There was a lot more to the Maya calendar than just 13 baktuns," Stuart observed. Seventeen baktuns would stand for about 6,700 years, which is much longer than the 13-baktun cycle of 5,125 years. However, Stuart cautioned that the time notation shouldn't be read as specifying a date that's farther in the future than Dec. 21.

"It may just be that this is a mathematical number that they find interesting, kind of floating in time," he told me. "But it certainly is expressing a capacity of time. If they were calculating something from their time period, around 800 A.D., yeah, this would have gone way beyond 2012. But again, we're not sure exactly what the base of the calculation is."

William Saturno and David Stuart / National Geographic

Four long numbers on the north wall of the ruined house relate to the Maya calendar and computations about the moon, sun and possibly Venus and Mars; the dates may stretch some 7,000 years into the future. These are the first calculations Maya archaeologists have found that seem to tabulate all of these cycles in this way. Although they all involve common multiples of key calendrical and astronomical cycles, the exact significance of these spans of time is not known.

Saturno said archaeologists have been trying to get out the word that the end of the Maya culture's 13-baktun "Long Count" calendar didn't signify the end of the world, but merely a turnover to the next cycle in a potentially infinite series — like going from Dec. 31 to Jan. 1 on a modern calendar, or turning the odometer on a car over from 99999.9 to 00000.0.

"If someone is a hard-core believer that the world is going to end in 2012, no painting is going to convince them otherwise," he said. "The only thing that can convince them otherwise is waiting until Dec. 22, 2012 — which fortunately for all of us isn't that far away."

Saturno and his colleagues plan to be studying the Xultun site long after that time. He said the workshop was apparently part of a residential compound that had been razed over the ages; the workshop was preserved because it was filled in with material rather than smashed down from above. That could suggest that the room was recognized as a special place even when it was abandoned. Research into the room and its purpose is continuing, Saturno said.

In its day, Xultun apparently served as one of the major ceremonial cities for the Classic Maya civilization — and yet it's just barely been explored, in part because the area is so remote.

"We have probably 99.9 percent of Xultun left to explore," Saturno said. "We're going to be working on it probably for many decades to come. ... Four or five years in to the research project, we have yet to determine its actual boundaries — so my estimate may be off. We may have 99.99 percent left to excavate."

More Maya mysteries:

• How the Maya lived
• Maya myth revealed in stucco
• Maya doom teaches climate lesson
• Even the Maya are sick of 2012 hype
• Gallery: Seven archaeological mysteries

In addition to Saturno and Stuart, authors of the Science paper, "Ancient Maya Astronomical Tables from Xultun, Guatemala," include Anthony Aveni and Franco Rossi. The Xultun excavations between 2008 and 2012 were supported by Boston University and the National Geographic Society.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

University of Arizona law student Gregory Schneider is getting ready for graduation this weekend, for the birth of his third child later this year — and now he'll have to get ready for a spaceflight as well.

Schneider accepted his prize during a Seattle Space Needle ceremony today from none other than 82-year-old Buzz Aldrin, one of the first men to walk on the moon in 1969. The suborbital trip into space, aboard a craft that's yet to go into operation, was the first prize in a "Space Race 2012" contest organized to mark the 50th anniversary of the 1962 Seattle World's Fair. Schneider was selected from 50,000 people who entered the contest, and out-competed a fellow finalist, Sara Cook of Washington, D.C., during a last round of physical and mental tests this morning.

Schneider teared up as he talked about what the spaceflight prize meant to him. "The more people we can get to see the world from a different perspective, the closer we can all come," he said.

Just before he awarded the prize, Aldrin also reflected on the opening of the space frontier. "July 20, 1969, changed my life forever," he said, referring to the date of the Apollo 11 moon landing. "Maybe it's not as great as that, but the life of one of these two people is going to be changed when I open up this envelope."

Alan Boyle / msnbc.com

Sara Cook gets ready to climb up a ladder to the top of the Seattle Space Needle's antenna during today's "Space Race 2012" challenges.

The final rounds
Five finalists came to Seattle for this week's finals, and Schneider and Cook came out on top after racing remote-controlled rovers, putting together a simulated solar panel, and doing mental and physical tasks while floating in an indoor-skydiving arena. This morning, they were brought to the Space Needle for the high-wire finals. The first task was to shinny up a ladder to the very top of the Space Needle's antenna and set off an air horn. Schneider's 29.69-second performance gave him say over whether he went first or second in the final competition.

Then the contestants were hooked up with safety equipment and put out on the Needle's "Halo," a narrow, open-air ring circling the monument's 520-foot-high observation deck. The challenge was to walk around the Halo, periodically writing down the answers to word and trivia puzzles that were posted at 10 points on the course. (Two examples: Unscramble the word PALOLO ... and tell how many stars are in the Big Dipper.)

First Schneider, then Cook, took a turn. The times were recorded, with penalties added for missed answers. The brain-teasers turned out to provide the margin of victory: Cook answered four of them correctly, but Schneider got eight right.

Aldrin marveled at the two finalists' performance: "I've been kind of out and back," he said, "but you wouldn't catch me walking around that Space Needle. I'm afraid of heights."

Space dreams
Schneider said it's been his dream to fly in space, but the main reason he entered the contest was for his children — a 7-year-old daughter and a 3-year-old son. "I thought of it as an opportunity to inspire my kids," he told me.

Cook, 24, who works for the Japanese Embassy in Washington, was also following through on long-held space aspirations. "I dreamed of being an astronaut when I was a child. ... I just couldn't not enter," she said. And even though she fell just short this time around, she hasn't given up her dream of going into outer space.

"If it became more affordable, I would love to," she said.

It'll be a while before Schneider gets to use his prize, which is valued at $110,000. The flight is being offered by Space Adventures, a Virginia-based travel company, on a craft that is currently being developed by Texas-based Armadillo Aerospace. That development effort hasn't yet progressed far enough to set a date for the start of commercial service.

Alan Boyle / msnbc.com

Apollo 11 moonwalker Buzz Aldrin counts down at right as Space Race 2012 contestant Gregory Schneider gets set to make his way through a puzzle course on the "Halo" of Seattle's Space Needle.

Alan Boyle / msnbc.com

Gregory Schneider discusses his spaceflight dreams after winning a future suborbital trip, plus a trophy in the shape of the Space Needle (left). Sara Cook gets set to climb up the Needle's antenna (right).

Schneider thus joins a long list of other contest winners who are waiting to take a spaceflight. Based on the current outlook, the first of those contestants might take suborbital trips in 2013 or so, when Virgin Galactic is expected to begin commercial service with the SpaceShipTwo rocket plane.

The kinds of trips being planned by Virgin Galactic, Armadillo Aerospace, XCOR Aerospace, Blue Origin and others taking aim at the suborbital travel market would bring passengers just beyond the 62-mile (100-kilometer) boundary of outer space, then back down to the place they started from. It may not be as high-flying as Aldrin's trip in 1969, but it would give the passengers a few minutes of weightlessness, some roller-coaster thrills, and a view that's even better than the view from the Space Needle. That's what Schneider is looking forward to the most.

"It's going to be absolutely incredible to see the earth ... as a cosmic object that's out there in space," he told me.

Did you get the answers right? APOLLO, and seven stars in the Big Dipper.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Hebrew University of Jerusalem

Yosef Garfinkel, an archaeologist at the Hebrew University of Jerusalem, shows off an ark, or stone shrine model, that was found during excavations at Khirbet Qeiyafa, an ancient settlement southwest of Jerusalem.

An archaeological dig near Goliath's biblical hometown has yielded evidence of Judean religious practices 3,000 years ago, pointing up fresh historical connections to the stories of King David and King Solomon.

"We have a city with a population relating to the Kingdom of Judah," Yosef Garfinkel, an archaeologist at the Hebrew University of Jerusalem, told me today. "This is totally different from Philistine, Canaanite or the cult in the Kingdom of Israel."

The site, known today as Khirbet Qeiyafa, is about 20 miles (30 kilometers) southwest of Jerusalem, on top of a hill overlooking the Valley of Elah. For the past five years, Garfinkel and his colleagues have been excavating the ruins of a fortified city there, situated across from what was once the Philistine city of Gath. In the Bible, the giant Goliath came out from Gath to face the Israelites, and was smitten by a rock hurled from David's sling.

Garfinkel can't vouch for the story of Goliath, but he says the weapons, the cult items and even the animal bones found around Khirbet Qeiyafa support his view that the settlement was a key military outpost for the historical House of David, riven by conflict. "There was something here quite military and quite aggressive," he said. "It was not a peaceful village."

Based on radiocarbon dating of burned olive pits found at the site, archaeologists believe the ancient city lasted for only 40 years, from 1020 to 980 B.C., before it was destroyed. Some skeptics have suggested that Khirbet Qeiyafa was just another Canaanite settlement, and that David was at best a minor chieftain, or perhaps a folkloric figure like Robin Hood. But Garfinkel said the items found at the site strengthen the connection to King David and the religious practices specified in the Bible.

"Over the years, thousands of animal bones were found, including sheep, goats and cattle, but no pigs," he said in a news release from the Hebrew University of Jerusalem. "Now we uncovered three cultic rooms, with various cultic paraphernalia, but not even one human or animal figurine was found. This suggest that the population on Khirbet Qeiyafa observed two biblical bans — on pork and on graven images — and thus practiced a different cult from that of the Canaanites or the Philistines."

Garfinkel told me that the absence of human imagery was peculiar to the Judeans. "In the northern Kingdom of Israel, you find human representations," he said.

Hebrew University of Jerusalem

One of the cultic standing stones can be seen in this picture of the Khirbet Qeiyafa site.

Hebrew University of Jerusalem

This basalt altar was found during excavations at Khirbet Qeiyafa.

Hebrew University of Jerusalem

A decorated clay shrine model was found at the Khirbet Qeiyafa site.

The cult objects included five standing stones, two basalt altars, two pottery libation vessels and two portable shrines. Garfinkel said the shrines reflected a Mesopotamian architectural style that went back centuries before the era of King David, and probably inspired the look of the palace built by Solomon, David's son. "It seems that Solomon didn't want to be Canaanite and took a different model from Mesopotamia," Garfinkel told me.

The shrines are boxlike containers made of stone or clay. "I think they were called in Hebrew 'Aron,'" Garfinkel wrote in an email. "This had been translated into English as 'ark' and became a mystic artifact. I think that the Hebrew name was just a simple technical term: a box for keeping god symbols."

Such shrines were probably similar in look to the "Ark of God" highlighted in the Bible as well as in such movies as "Raiders of the Lost Ark."

The clay shrine has an intricate facade, featuring two guardian lions, pillars and birds standing on the roof. The stone shrine was painted red, and its facade is decorated with characteristic triglyph symbols as well as a triple-recessed doorway in front. Garfinkel said the Bible may have referred to those architectural features in its description of Solomon's palace. The technical term usually translated as referring to pillars ("Slaot") may actually be talking about triglyphs, while another term that was thought to refer to windows ("Sequfim")  might instead refer to the doorways.

"Now you can see by the model that you have triglyphs at the roof, and you have recessed doorways," Garfinkel said. Such features are also mentioned in biblical references to King Solomon's temple, which was built decades after the age that gave rise to the shrines found at Khirbet Qeiyafa.

Will these finds settle the debate over the historical David? Garfinkel would like to think so. "Various suggestions that completely deny the biblical tradition regarding King David and argue that he was a mythological figure, or just a leader of a small tribe, are now shown to be wrong," he said in today's news release.

But The Times of Israel quoted Bar-Ilan University's Aren Maeir, who's in charge of the dig at Gath, as saying the discoveries don't provide any dramatic new evidence for either side in the debate. For example, the fact that the clay shrine was decorated with lions and birds undercuts Garfinkel's claim that no graven images were found at the site. The Israeli newspaper Haaretz quoted another expert, Tel Aviv University's Nadav Na'aman, as saying that the Canaanites, like the Judeans, observed a ban on eating pork.

Maeir said the distinctions between the various peoples mentioned in the Bible — including David's Israelites and Goliath's Philistines — were "fuzzier than the way they are often described."

"There's no question that this is a very important site, but what exactly it was — there is still disagreement about that," Maeir said. In a blog posting, Maeir said "what is clearly missing is a close interface with mainstream biblical and [Ancient Near East] textual scholars." 

What do you think? Feel free to weigh in with your vote in the poll above, or add your comments below.

More about biblical archaeology:

• In Israel, diggers unearth the Bible's bad guys
• Dig yields what may be the oldest Hebrew text
• Artifact suggests Bible written centuries earlier
• Professor hunts for the 'Lost Ark of the Covenant'
• Gallery: Eight Jewish archaeological discoveries
• Cosmic Log archive on archaeology

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Nicolle Rager Fuller / NSF

An artist's conception shows an RNA molecule, which may have served as an early form of life on Earth.

The debate over the definition of life is getting messier and messier, but one of the pioneers on the biochemical frontier is suggesting a method to tell whether scientists are actually looking at a new form of life: Follow the bits of information that are contained in the chemistry.

"How many heritable 'bits' of information are involved, and where did they come from?" Scripps Research Institute biologist Gerald Joyce asks in an essay published today by the journal PLoS Biology. "A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life."

By that definition, we're not yet close to identifying alien life, in the lab or in the cosmos, Joyce told me today. "The fact is, there is only one known form of life, and we're part of it. Someday, maybe there'll be something that's off the grid, but everything we know is part of the tree of life."

Joyce says that verdict applies to microbes with artificially constructed DNA, such as the bacteria that were built in a lab two years ago, as well as to the arsenic-tolerant bacteria that were at one time touted as a form of alien life. He worries that all these claims about creating or finding alien life could backfire.

"We've had enough of these false alarms that I'm getting a little nervous that the public is going to perceive it as 'crying wolf,'" he said. "There have been enough examples that we need to just cool it a little."

Joyce applies the same rule of thumb to his own research, which focuses on RNA enzymes that can be combined to create a synthetic genome. In the essay, he notes that the RNA enzymes can "evolve" into new forms, but contain only 24 bits of their own heritable information in the form of chemical base pairs. The molecules need another 60 bits of information that are provided at the outset and are not subject to mutation and selection.

"Thus, of the 84 total bits required for the system to replicate and evolve, only about one-fourth can be counted as part of the system's molecular memory," he writes. "The synthetic genetic system is not a new life form because it operates mostly on borrowed bits."

Creating or remaking life in the lab
Is it even possible to come up with a life form from scratch? That's one of the key reasons for having a working definition, so that scientists know alien life when they see it ... or make it. The synthetic bacteria created by J. Craig Venter and his colleagues wouldn't qualify because those microbes are merely using a computerized genetic code that was tweaked from nature. "Craig Venter knows that he didn't make a new life form. He remade Mycoplasma," Joyce said.

But if RNA enzymes — or another class of synthetic molecules known as xenonucleic acid polymers or XNA — could be developed into stand-alone genetic systems, with more than half of the information passed along through an alternate chemistry, that just might lead to a truly new form of life.

"That's definitely knocking on the door ... What you'd need is an XNA molecule that has the function of copying XNA parent molecules to produce XNA progeny with pretty good fidelity," Joyce said. Right now, the XNA bits have to be swapped into DNA for amplification, he noted.

Life on other worlds
Joyce said alien life could be created in the lab, or its fingerprints could be detected far from our solar system. "About a decade from now, we're going to start seeing the atmospheric composition of extrasolar planets," he said. If future telescopes pick up the signs of unusual chemistry — say, an unexpected excess of ozone — that could point to potential life processes. But to clinch the case, scientists would need to learn enough about the mechanism behind the chemistry, and how that chemistry preserves "molecular memory" from one generation to the next.

"To me, in a slogan, biology is chemistry plus history," Joyce said. "There's a special class of chemistry that has memory, that has history built in. It's a kind of chemistry that learns from experience."

Confirming the existence of biological-style chemistry on Mars, or in some other environment in our own solar system, presents a special case. "Now we're really in the game," Joyce said. "We're talking about 'spit-carrying molecules.' Maybe we can get little snippets of information and start stitching that together, and have enough to say, 'OK, is it on the tree of life or not?' If the sequence is just off the tree, was it a deep branch, or did it become its own thing?"

Joyce said the alien-life debate could well be reignited by developments right here on Earth, such as the analysis of samples brought up from Lake Vostok, a freshwater lake hidden beneath a miles-thick layer of Antarctic ice. "I won't be surprised, when the samples come up from James Cameron's deep dive to the Mariana Trench, that someone starts thinking that there's something weird down there," he said in a PLoS Biology podcast. "Maybe it's an alternative life form."  

One thing's for sure: Until another truly alien form of life is created or discovered, it's impossible to make a meaningful estimate of how common life might be in the universe, or arrive at the answer to one of life's ultimate questions: Are we alone?

"I think humans are lonely, and long for another form of life in the universe, preferably one that is intelligent and benevolent," Joyce said in a PLoS news release. "But wishing upon a star does not make it so. We must either discover alternative life or construct it in the laboratory. Someday it may be discovered by a Columbus who travels to a distant world or, more likely in my opinion, invented by a Geppetto who toils at the workbench."

More about life, the universe and everything:

• Can scientists define 'life' ... using just three words?
• What should society do about synthetic life?
• Gallery: Six signs that aliens might actually exist
• What exactly is life?

In the PLoS Biology podcast, Joyce discusses the search for new life forms and synthetic biology. Joyce's work was supported by NASA and the National Science Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Mariana Ruiz Villareal

Calculations of dinosaur biomass suggest that plant-eating sauropods like the ones pictured here in an artist's conception could have contributed enough methane to warm Earth's climate 150 million years ago.

Some scientific findings are just too good to leave alone, even if you don't know if they can ever be confirmed: Such is the case for a study saying that plant-eating dinosaurs could have emitted enough digestive methane to warm Earth's climate 150 million years ago.

"It is known that the time of these dinosaurs was warmer than now," said David Wilkinson, an environmental scientist at Liverpool John Moores University who's the lead author of a paper on the subject appearing in the journal Current Biology. "This is explained usually by an enhanced greenhouse effect, mainly carbon dioxide. If we are correct, then methane from sauropods may have been a contributor to this greenhouse effect."

Methane is a more potent greenhouse gas than carbon dioxide, and modern-day livestock are thought to be responsible for about a quarter of the methane released in the United States. Some say that the belches and flatulence of cattle, pigs and sheep are a significant contributor to the warming effect caused by greenhouse-gas emissions. So why wouldn't it have been the same in the age of giant plant-eating dinosaurs, when global biomass density was at least several times what it is today?

"All vertebrates that feed on leaves, etc., use microbes to help digest these, and usually give off methane," Wilkinson told me in an email. "This includes both mammals and reptiles. ... Although details vary within groups, everything around today does this, so the assumption is [that] larger herbivorous dinosaurs did as well."

He and his colleagues ran the numbers, using what they saw as conservative estimates for the total amount of dinosaur biomass and methane production rates per kilogram of body mass. They came up with a figure of 520 million tons of methane emitted per year, which is more than total modern-day methane emissions from all sources, natural and industrial. The current estimate for total methane emission is around 500 million tons a year, with 50 to 100 milllion tons of that coming from ruminant animals such as cows and goats, Wilkinson said.

"Our work certainly suggests biology and climate were involved in a feedback loop," he said.

Biologists have found that most of the modern-day methane emissions from livestock come from belching rather than flatulence. Was it the same for dinosaurs? "We have no particular view which end of the sauropod the methane came out," Wilkinson told me. "Could be either or both."

Chemical analysis of ancient marine sediments has found that greenhouse-gas levels went through a huge rise 201 million years ago, around the time of a mass extinction that set the stage for the rise of the dinosaurs. Scientists suspect that the atmospheric methane levels at that time were pumped up by a massive release of methane from the seafloor. Such evidence suggests that plant-eating dinosaurs weren't responsible for starting the upswing in Mesozoic methane. But did they help preserve the methane-rich atmosphere and toasty temperatures until they were killed off by an asteroid strike?

Wilkinson noted that his paper was titled "Could Methane Produced by Sauropod Dinosaurs Have Helped Drive Mesozoic Climate Warmth?" — not "Did Methane Produced by Dinosaurs Help Drive Climate Warmth."

"What our simple calculations show is that, yes, it could. It's a real possibility. But we don't show that it did happen," he said. "That would require much more work, and indeed it may be impossible to completely prove this without a time machine."

Extra credit: A dozen years ago, the BBC quoted a Chinese news report that quoted an unnamed French scientist as saying the dinosaurs were wiped out 65 million years ago not by an asteroid, but by their own flatulence. This hypothesis proposed that the methane emissions from the giant beasts became so great that the climate changed, the vegetation withered and the dinosaurs all starved. But that's just too silly to consider. Or is it?

More about methane:

• U.S. claims success in fuel source test
• Herb quells cows' methane-laden belches
• Did methane 'burp' clear way for dinosaurs?
• Methane seeping from ice becomes climate concern

In addition to Wilkinson, authors of the Current Biology paper include the University of London's Euan G. Nisbet and the University of Glasgow's Graeme D. Ruxton.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

The supermoon of 2012 is over, but the joys of moongazing are not. Even though Saturday night's lunar showing was the biggest and brightest of the year, the views are nearly as good anytime around the full moon — tonight, for example.

Photographs of the supermoon sight streamed out over online channels, including Twitter feeds, Facebook updates, blog postings and slick slideshows (such as our own roundup). They also streamed into msnbc.com's FirstPerson in-box. I've put together a selection of 10 submissions here.

The kind of supermoon we saw last night isn't exactly a once-in-a-lifetime occurrence. The phenomenon, also known as a perigee moon, can be seen whenever the full moon occurs while it's near the closest point of its elliptical orbit around Earth. Last night, the moon was just 221,802 miles away from Earth, or about 15,000 miles closer than average. The moon's angular size was 14 percent wider than it is at maximum distance, and it was 30 percent brighter than minimum moonshine.

If we define a supermoon as the biggest, brightest full moon of a given year, next year's supermoon will be almost as good as this year's, on June 23, 2013. The supermoon of 2014 will be brighter, and the 2016 supermoon will outdo last year's, which got the moongazing fad started. EarthSky News has the schedule for the next few years. Some rightly note that the moon is worth watching on every night of the year, and that the full moon isn't necessarily the best time to see all the detail the lunar disk can offer. But there's nothing wrong in having an annual holiday devoted to moongazing, is there?

The next big sky event is coming up on May 20, when the new moon blots out most of the sun to create an annular solar eclipse. A wide swath of the Asia-Pacific region and North America will see a partial eclipse, while folks situated along a narrow track of territory extending from China across to the Oregon-California coast and down to Texas can witness a "Ring of Fire," in which the moon's disk covers all but the thin rim of the sun's disk. That'll be an amazing thing to see, but make sure you use proper eye protection. You can get the details from my eclipse viewing guide, and learn more about the appeal of an annular eclipse.

There's an astronomical connection between this weekend's supermoon and this month's "Ring of Fire": Because the moon was nearly as close as it can come for the full-moon phase, it's nearly as far out as it can go for the new-moon phase. Thus, the moon's apparent size is significantly smaller than usual when it tries to covers up the sun — and that's why we have a ring of fire rather than the fully blacked-out sun of a total eclipse. For that, we'll have to wait until November. Stay tuned in the weeks and months ahead for more about all these astronomical phenomena, plus June's last-in-a-lifetime transit of Venus.

Submitted by Isaiah Blount / Smooth Images / UGC

Florida photographer Isaiah Blount of Smooth Images submitted this picture of an airplane crossing the disk of the supermoon on Saturday night.

Submitted by Penny Wainwright / UGC

The supermoon looms in the skies of Louisiana, outside Farmerville.

Submitted by Campbell McCubbin / UGC

Campbell McCubbin says this is the "first glimpse of the 'supermoon' from my deck overlooking Semiahmoo Bay, White Rock, B.C., Canada."

Submitted by Prashanti Pasupuleti / UGC

Prashanti Pasupuleti of New Delhi, India, says the supermoon is "within my reach."

Submitted by Angie Lucero / UGC

Wisps of clouds waft over the supermoon in this view from Albuquerque, N.M.

Submitted by Maria Johnson / UGC

Maria Johnson took this picture of the moon around 1 a.m. ET on Sunday in Sarasota, Fla.

Submitted by Larry Shiflett / UGC

The supermoon rises over a sailboat in the waters near Fort Lauderdale, Fla.

Submitted by Bianca Fister / UGC

Spring flowers are silhouetted against the supermoon in this picture from Bianca Fister of Hilton, N.Y.

Submitted by Joe Leonard / UGC

The supermoon peeks over the Sangre de Cristo Mountains in a picture from Joe Leonard of Taos, N.M..

Submitted by Justine Daniel / UGC

The supermoon is partly hidden by clouds in the skies above St. Augustine on the island of Trinidad.

More about the supermoon:

• Slideshow: Greatest hits from the supermoon
• How big is that supermoon anyway?
• Wonders of sun, moon and sky
• Five moon mysteries
• Five moon myths

Many thanks to all our FirstPerson photographers, including Lynn Schneider, John McNamara, Josh Warner and Mitzi Easley.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Robert Michael / AFP - Getty Images

A nearly full moon rises behind the cross of the Frauenkirche in the German city of Dresden in May 4.

Saturday night's "supermoon" is the biggest and brightest full moon of the year, due to the fact that the moon is near the closest point in its orbital path around Earth. But just how much bigger and brighter does it look? That's a tricky question.

Most reports say the moon looks 14 percent bigger than usual, which is close to the truth but isn't quite right. They also say it's 30 percent brighter than usual, which isn't right, either. James Garvin, chief scientist at NASA's Goddard Space Flight Center, ran the numbers to come up with an explanation that seems to make the most sense.

First of all, it's important to note that the moon itself is not getting significantly bigger or smaller. There's a scientific debate over whether the moon is slowly shrinking or spreading out. But in either case, the change isn't noticeable on human time scales.

The difference in the moon's apparent size is basically a function of how close it is to Earth in its elliptical orbit. That orbit isn't changing on human time scales, either. It just so happens that tonight, the moon is coming closest to Earth at the same time that it's going full. Because the moon and the sun are precisely opposite each other, relative to Earth, tonight's ocean tides may be a bit higher than typical — but again, the effect is nowhere near big enough to worry about.

So how noticeable is the visual effect? Here what Garvin told me in an email today:

• "The biggest predictable effect on the brightness of the full moon is how close the moon is to Earth.  With everything else the same, a full moon is about 30 percent brighter when the moon is closest to Earth in its orbit (called perigee) compared to a full moon when the moon is farthest from Earth in its orbit (called apogee).  Today’s full moon is at perigee."
• "Also, when the moon is high in the sky (as it is now), we are closer to the moon by approximately the radius of Earth compared to when the moon is on the horizon. (Note: Earth’s radius is about 6,371 kilometers)."
• "Since the distance from the center of Earth to the center of the moon is on average about 384,403 kilometers, the radius of the earth is about 6,371 kilometers, and brightness changes as the square of the distance, being closer to the moon by about the radius of the earth increases the brightness of the full moon by about 3 percent."  
• "Thus the present supermoon is, at maximum, only about 9 to 10 percent larger in an angular (appearance) sense than a typical full moon and is also brighter (by a few percent), making it appear 'super.'"

"Meanwhile, our intrepid Lunar Reconnaissance Orbiter continues its remarkable mapping of our nearest celestial neighbor, coming up (in June) on its three-year anniversary of being in lunar orbit with its amazing array of 7 instruments," Garvin added.  "As of now, the data returned from LRO (over 300 trillion bytes) is larger than all of the rest of the data acquired for planets in the solar system combined (except for Earth, of course)."

Which just goes to show that every day is a "super moon" day for the Lunar Reconnaissance Orbiter and its science team. Check out NASA's Web site for more wisdom from James Garvin.

Geoff Chester, an astronomer at the U.S. Naval Observatory, says the moon appears 14 percent larger in angular size when it's at the closest point in its orbit, compared with its appearance when it's farthest away from Earth. That's not 14 percent larger than average. That's 14 percent larger than the minimum apparent size.

"You'd be very hard-pressed to detect that with the unaided eye," Chester told The Associated Press. Seasoned skywatchers, however, say they can definitely tell the difference. Can you? Take a look at the moon tonight — before, during or after the moment of maximum fullness at 11:35 p.m. ET — and tell us what you see.

Update for 6:45 p.m. ET May 5: Bad Astronomy's Phil Plait observes that the moon's angular size is roughly equivalent to that of a dime as seen from 6 feet away. You can bet I'll have a dime taped onto a south-facing window tonight to make the observations. Also, tonight's supermoon will be a little less super than last year's supermoon, because the moon is about 240 miles farther away at peak fullness than it was in March 2011. For what it's worth, next year's supermoon will be imperceptibly smaller than this year's. I wonder if there'll be perceptibly less hype.

Update for 2:20 a.m. ET May 6: Yes, the weather was clear enough for supermoon-gazing in my Seattle-area neighborhood — and yes, I really did tape a dime onto a window to compare its angular size with the moon's. But it seemed to me that the sizes were about the same at a dime distance of 4 or 5 feet, rather than the 6-foot distance that Phil Plait suggested. Which just goes to show you: YMMV (your moon may vary). You can see what I saw by checking my Twitpic gallery.

More about the supermoon:

• How to see the supermoon — and meteors, too
• How to plan your supermoon snapshot
• Supermoon rises over Greek temple
• Five moon mysteries
• Five moon myths

If you snap a great photo of the moon, feel free to upload it into msnbc.com's FirstPerson in-box.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Monika Landy-Gyebnar

Monika Landy-Gyebnar took this picture of the rising sun on May 1 from Veszprem, Hungary. "The image I saw when the sun appeared was incredible!" she said in a posting to SpaceWeather.com. "This was the strongest mirage effect on the sun I have ever seen!" In this image, the mirage makes the sunspot region known as AR 1471 look like three dots in a row, toward the lower left area of the sun's disk.

The next month promises to be filled with astronomical wonders, including this weekend's "supermoon," an annular solar eclipse later this month, and a last-in-a-lifetime transit of Venus. Here are a few images to get you in the mood for those cosmic glories.

Hungarian photographer Monika Landy-Gyebnar snapped an unusual picture of a solar mirage on May 1, showing the sun's distorted disk at the eastern horizon. She told SpaceWeather.com that she expected to see the mirage, because she lives in an area where morning fog usually collects in the valley, "so it is a location colder than its surroundings." The temperature difference often creates a shimmering mirage effect, but Landy-Gyebnar was amazed by the strength of the effect on that particular morning.

"The distortion reached the region where the big sunspot 1471 is located as a visible dark dot," she wrote. "I saw the sunspot disappearing and appearing again, then its mirage appeared above the original spot higher on the solar disk, then a third mirage spot appeared. ... I was shivering with beauty!"

For details, check out Landy-Gyebnar's gallery at SpaceWeather.com and her video clip on YouTube.

The picture above served as today's "Where in the Cosmos" picture puzzle on the Cosmic Log Facebook page, and Brittany Pedersen was the first to figure out that the photo showed a sunspot mirage. To reward her sharp vision, I'm sending her a pair of solar viewing glasses from Astronomers Without Borders. Stay tuned for the next "Where in the Cosmos" quiz on Facebook in a week, and you might win some solar spectacles as well.

Landy-Gyebnar's photographs, and the glasses, serve as good reminders that skywatchers should never gaze at the shining sun without proper eye protection, even during the annular solar eclipse coming up on May 20. To get ready for that rare event, check out my two-part series and "Virtually Speaking" podcast.

Another big sky event is coming up this weekend, when the moon turns full during its closest approach to Earth. That means the moon will be 14 percent bigger and 30 percent brighter than the norm — leading many to call the sight a "supermoon." So much has been made of Saturday night's full moon that Bad Astronomy's Phil Plait is counseling rhetorical restraint (with an artistic assist from Sci-ence's Maki Naro). But even Phil says it's worth going out and looking at the moon, on Saturday night or on any night. "It's bright and silvery and lovely and you can see features with your naked eye and with a telescope you'll see tons more," he writes.

If you have a great supermoon picture to share, please pass it along via msnbc.com's FirstPerson "Sky Highlights" upload page. We'll put together a gallery of our favorite moon views over the weekend.

The Hubble Space Telescope has been looking at the moon lately, in preparation for the transit of Venus on June 5. That's when the planet Venus makes a stately march across the disk of the sun over the course of six hours. The last time Venus did that was eight years ago, and it won't happen again until the year 2117. So the scientists behind Hubble, like many other astronomers, want to take a look.

As explained in today's image advisory, the sun is too bright for Hubble to observe directly. Instead, Hubble's scientists will check the light rays that are reflected by the moon and see whether they can discern the faint signature of the light that passed through Venus' atmosphere.

"Imprinted on that small amount of light are the fingerprints of the planet's atmospheric makeup," the Hubble team said in its advisory. "These observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus's atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earthlike planet, even one that might be habitable for life, outside our solar system that similarly transits its own star."

Hubble will observe the moon for seven hours on the day of the transit to get a good sampling of spectroscopic data. Here's a practice image of the impact crater Tycho, acquired on Jan. 11: 

D. Ehrenreich / IPAG / CNRS / UJF / NASA / ESA

This mottled landscape showing the impact crater Tycho is among the most violent-looking places on our Moon. Astronomers didn't aim NASA's Hubble Space Telescope to study Tycho, however. The image was taken in January as part of the preparation for observing the transit of Venus across the sun's face on June 5.

Finally, here are a couple of videos to end the week with: On one end of the time spectrum, there's an hourlong recap of this week's Space Hangout, in which several space scribes (including yours truly) review the far-out news of the week. On the other end, there's a six-minute mashup of cosmic images from NASA, titled "Pursuit of Light." The montage starts out with Earth imagery, then moves on to shots of the moon, the sun, Mars, Jupiter and its moons, the Saturnian system and asteroids. Then you'll see nebulas, the remnants of supernova blasts, and interacting galaxies. How much farther out can you get?

More far-out imagery:

• NASA probe captures close-ups of Saturnian moons
• Earth's beauty dazzles in astronaut video from space
• Slideshow: Month in Space Pictures for April 2012

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

SpaceX

Sparks and clouds of exhaust and vapor issue forth from SpaceX's Falcon 9 rocket during a static fire test at Cape Canaveral Air Force Station on Monday.

SpaceX has suggested May 19 as the new date for its potentially history-making Falcon 9 rocket launch to the International Space Station, with May 22 as a backup date.

The schedule shift provides more time for NASA to review changes in the California-based company's flight software, and also avoids a potential conflict with the planned May 14 launch of three new space station crew members from Russia's Baikonur Cosmodrome in Kazakhstan.

If SpaceX's demonstration mission is completely successful, it would represent the first commercial flight to the space station. The flight plan calls for the company's robotically controlled Dragon cargo capsule to conduct a series of maneuvers near the station, starting two days after the Falcon 9 lifts off from Cape Canaveral Air Force Station's Launch Complex 40 in Florida. If all those maneuvers go as planned, astronauts on the orbiting outpost would latch onto the Dragon and pull it in for a berthing.

About a half-ton of supplies would be unloaded over the course of a couple of weeks, and then the Dragon would be detached and sent back down to a Pacific Ocean splashdown. That success scenario would open the way for SpaceX to start resupplying the space station in earnest, under the terms of a $1.6 billion contract with NASA.

If the Dragon couldn't hook up with the station this time around, another demonstration flight would be scheduled as a makeup test.

SpaceX has received hundreds of millions of dollars from NASA to develop the Falcon 9 and the Dragon as a partial replacement for the space shuttle fleet, which was retired last year. The Falcon 9 had a successful maiden orbital flight in June 2010, and the Dragon made a similarly successful debut in December 2010. The upcoming flight would provide the first opportunity for an actual rendezvous with the space station.

The launch has been repeatedly delayed, primarily due to flight software reviews. SpaceX conducted a successful launch-pad engine firing test on Monday in preparation for a planned May 7 liftoff, but the company and NASA decided to hold off in order to provide more time for the current review.

"SpaceX and NASA are nearing completion of the software assurance process," company spokeswoman Kirstin Brost Grantham said today in an email, "and SpaceX is submitting a request to the Cape Canaveral Air Force Station for a May 19 launch target with a backup on May 22. Thus far, no issues have been uncovered during this process, but with a mission of this complexity we want to be extremely diligent."

Bill Gerstenmaier, NASA's associate administrator for human exploration and operations, also indicated in a space agency statement that the May 19 date was doable.

"After additional reviews and discussions between the SpaceX and NASA teams, we are in a position to proceed toward this important launch," he said. "The teamwork provided by these teams is phenomenal. There are a few remaining open items, but we are ready to support SpaceX for its new launch date of May 19."

Because of the orbital mechanics involved with a space station rendezvous, the Falcon 9 must be launched at a precise time of day, with opportunities coming up only every three days.

The current plan would result in a launch at 4:55 a.m. ET May 19. That would provide an ample time interval after the Russians' launch of a Soyuz craft carrying a NASA astronaut and two Russian cosmonauts up to the station. That mission, which is due for liftoff on May 14 Eastern time and docking on May 17, will boost the station's crew to its full complement of six spacefliers.

More about SpaceX:

• SpaceX chief plans to become spaceflier
• Next steps in the new space race
• SpaceX has a lofty goal: Help save humanity
• CNBC: Elon Musk on why SpaceX has the Right Stuff
• Cosmic Log archive on the new space race

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

The prime target for the $10 billion Large Hadron Collider is discovery and study of the Higgs boson — but what the heck is the Higgs, and what's it supposed to do? PHD Comics' Jorge Cham explains the quest in an animated cartoon that draws upon the expertise of Daniel Whiteson, a particle physicist from the University of California at Irvine who's working at Europe's CERN research center.

The Higgs boson, sometimes referred to as the "God Particle," is thought to be the force-carrier for a field that endows subatomic particles with varying values of mass. British physicist Peter Higgs and others theorized that it must exist to fill out a gap in physics' Standard Model of particle physics, but it hasn't yet been detected. Scientists expect it to turn up at the LHC, or else they might have to go back to the drawing boards and rework the Standard Model.

Almost two decades ago, Britain's science minister challenged experts to come up with an everyday explanation for the way the Higgs worked, and physicist David Miller came up with a comparison to Margaret Thatcher making her way through a crowded cocktail party. Whiteson and Cham use the analogy of marbles rolling across a floor, which works, too. Check out the big-format animated version on the PHD Comics Web site or on Vimeo.

If physicists at the LHC get their way, the discussion of the Higgs boson could get a lot less theoretical by the end of this year, thanks to the increase in power levels and data return from the LHC and its particle detectors. However, Nature's Geoff Brumfiel reports today that the readings from hundreds of trillions of collisions are piling up so fast that the computers are having a hard time keeping up with the analysis. He writes that all those collisions are growing into a "thick fog" that threatens to obscure the signature of the elusive Higgs. Researchers are using clever computational techniques to separate the wheat from the chaff, data-wise, and are prepared to dial back the collision rate if necessary.

If it sounds as if the physicists have it rough, just imagine how the particles must feel. That's exactly what animator Karen Cheung, Oxford physicist Alan Barr and their colleagues did in a cartoon that was created for the Oxford Sparks Web portal. Enjoy!

More about the Higgs and the LHC:

• Higgs vs. hype: A mini-guide
• Can physicists crack the big puzzle?
• Flash graphic: Inside the Big Bang Machine
• Flash graphic: Michio Kaku on LHC nightmares and dreams
• Msnbc.com's special report on the Large Hadron Collider

Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

The billionaire founder of the SpaceX rocket venture, Elon Musk, says that within five years he wants to make orbital space trips available to regular passengers — including himself. And if he sticks to his timeline, Musk just might go beyond Earth orbit before NASA's Orion spaceships do.

"Am hoping to travel to orbit in about 5 years, beyond in 7 to 10," he wrote during a Twitter chat organized by The Associated Press. Later, he said it would be "5 years max before we fly civilians." That suggests that Musk is aiming to take an orbital trip in 2017 or so, along with paying passengers, and follow that up with more ambitious journey beyond Earth orbit in the 2019-2022 time frame.

In comparison, NASA's current schedule calls for astronauts to launch aboard its Orion multipurpose crew vehicle, the first NASA spacecraft since the Apollo era capable of taking a crew beyond Earth orbit, no earlier than 2021. The space agency is targeting its first manned mission to a near-Earth asteroid in the mid-2020s.

There are a few caveats to Musk's prediction. First of all, rocketry feats tend to take longer than Musk expects, as he himself acknowledged a couple of years ago during an interview. There's no better illustration of that than the buildup to SpaceX's history-making commercial cargo mission to the International Space Station, which has been delayed repeatedly over the past few months. The launch of SpaceX's Dragon capsule atop a Falcon 9 rocket at Cape Canaveral Air Force Station in Florida had been set for May 7, but SpaceX said liftoff would be held up while NASA was double-checking changes in the flight software.

Musk said today that he was "not surprised" by the latest holdup.

"This mission is super complicated, so delays are to be expected," he wrote during the chat. He said a new launch date would be selected in the "next few days."

This SpaceX mission is a test run, and it's not certain whether the Dragon will get all the way to its docking port on the space station's Harmony module this time around. If it does, that would clear the way for SpaceX to begin robotic cargo resupply missions in earnest later this year, under the terms of a multiyear $1.6 billion contract with NASA.

Musk, who plowed $100 million of his own dot-com fortune into SpaceX, is essential to the venture's success. He's not only the chief executive officer, he's also the company's chief designer and the chief engineer for the Falcon 9 and the Dragon. What's more, he's the CEO and product architect for Tesla Motors, an electric-car pioneer; and the non-executive chairman of SolarCity, a solar-panel company that's reportedly getting ready for an initial public offering.

His key role in so many ventures raises another caveat about that future space trip. Would Musk's investors let him go? On that score, the scenario could well play out the way it did in "The Man Who Sold the Moon," a novella by one of Musk's favorite authors, Robert Heinlein. The story focused on a tycoon who creates a wildly successful lunar venture — but whose dream to travel to the moon himself is frustrated by the venture's majority owners. They decide his blastoff would pose too much of a risk to their fortunes.

Speaking of Heinlein, Musk said during today's chat that "The Moon Is a Harsh Mistress," one of the sci-fi author's classics, ranks as a favorite book. The other books on top of Musk's reading list include "Ignition!" by John Clark, "Foundation" by Isaac Asimov and "Modern Engineering for Design of Liquid Propellant Rocket Engines" by Dieter Huzel and David Huang.

Musk also hit on the long-running theme that has motivated his rocket interest for more than a decade: making humanity into a multiplanet species. When asked what regular people could do to support SpaceX's efforts, Musk replied: "Rally people around the idea of making life multiplanetary with a base on Mars."

In past interviews, Musk has said it'd be possible for SpaceX to send humans to Mars in 10 to 20 years, and he truly believes that's the only way to ensure the species' long-term cosmic survival amid out-of-the-blue threats such as asteroid strikes.

"For humanity to have an exciting and inspiring future, we cannot be confined to Earth forever," Musk wrote. He said he was "highly confident that Mars can be self-sustaining without terraforming."

He returned to that theme in a video spot airing tonight on PBS' "NewsHour" program. "I'm talking about sending ultimately tens of thousands, eventually millions of people to Mars, and then going out there and exploring the stars," he said.

Does Musk have his head in the clouds? Or is it possible that the 40-year-old billionaire is on to something? Feel free to weigh in with your comments below.

More about SpaceX and Elon Musk:

• Next steps in the new space race
• Elon Musk says it'd be 'cool' to fly in space
• SpaceX has a lofty goal: Help save humanity
• CNBC: Elon Musk on why SpaceX has the Right Stuff
• Cosmic Log archive on the new space race

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

David Hughes / Penn State

This zombie ant has been taken over by a brain-manipulating fungus (Ophiocordyceps unilateralis s.l.), which in turn has been castrated by a hyperparasite fungus (white with yellow material).

The Cordyceps fungus has become a staple of "stranger than fiction" nature stories: Its complex and lethal parasitism of ants, causing the insects to climb as high as they can before the fungus bursts like a horn from their heads, is both bizarre and captivating. Now scientists report that the parasite is getting a dose of its own medicine, as it finds itself under attack from yet another parasitic fungus — one that targets Cordyceps. It's nature's way to pile weirdness upon weirdness.

Researchers led by David Hughes at Penn State University were looking into how some groups of ants were able to survive a Cordyceps attack. The fungus is extremely virulent and can often wipe out an entire colony. Ants groom each other to remove potentially troublesome fungus and microbes, but that couldn't account for the survival rates they were occasionally seeing.

What they found (and reported in PLoS ONE) was another fungus growing in and around the ant colonies — just as much a specialist as the first fungus. This newly discovered fungus attacked the "zombie-ant" fungi and effectively neutered them, sabotaging their spore-producing organs and preventing them from fruiting. Some ants would still be infected (the researchers described a "high density of zombie-ant cadavers in the graveyard"), but the spread of zombie-ism was largely stopped.

Each species of Cordyceps fungus targets only one species; the ant-zombifying variety is just the best-known type. That there could be a fungus that was parasitic in such a fascinating way on a single species is amazing enough, but that a second fungus would specialize in attacking the first is almost beyond belief. It's an example of the density and biodiversity that one finds in, as Hughes puts it, "the exciting theater played out on the rainforest floor."

In addition to Hughes, the authors of the PLoS ONE paper, "Disease Dynamics in a Specialized Parasite of Ant Societies," include Sandra B. Andersen, Matthew Ferrari, Harry C. Evans, Simon L. Elliot and Jacobus J. Boomsma. 

Devin Coldewey is a contributing writer for msnbc.com. His personal website is coldewey.cc.

SpaceX

The SpaceX Dragon capsule is prominent in this photo of the Falcon 9 rocket in its lowered position at Cape Canaveral Air Force Station's launch complex in Florida.

The first private-sector spaceship destined to hook up with the International Space Station will have to wait a few days longer than planned for its Florida launch.

SpaceX's Falcon 9 rocket had been scheduled to lift off from Cape Canaveral Air Force Station's Launch Complex 40 on May 7, on a test flight that could climax with a space station berthing of its unmanned Dragon cargo capsule several days later. A launch-pad engine test went off successfully on Monday, but more time is needed to analyze changes in SpaceX's flight software and make sure all systems are go.

"At this time, a May 7 launch appears unlikely," SpaceX communications director Kirstin Brost Grantham said in an email. "SpaceX is continuing to work through the software assurance process with NASA.  We will issue a statement as soon as a new launch target is set."

Due to the orbital mechanics involved in a space station rendezvous, the Falcon 9 can be launched only at a precise time during the day, on specific dates. The next opportunity for launch comes on May 10, but it's not yet clear whether liftoff will be reset for that date. In a Twitter update, Space News' Brian Berger cited an internal NASA manifest that showed the launch slipping to no earlier than May 10. After that date, SpaceX would have to stand down to let the Russians launch a three-person crew in a Soyuz craft to the space station on May 14.

California-based SpaceX has received hundreds of millions of dollars from NASA to support the development of the Falcon 9 and the gumdrop-shaped Dragon capsule for resupplying the space station. The Falcon 9 has been sent into orbit only twice before — once in June 2010 with a test capsule, and again in December 2010 with a functional Dragon spacecraft that returned to Earth after two orbits.

The upcoming demonstration launch has been rescheduled repeatedly, from February to April to May, due to the need for intensive software reviews. The flight plan calls for Dragon to execute a series of maneuvers near the space station. If the spaceship's sensors and flight systems work as designed, Dragon will then fly a rendezvous and approach. If Dragon reaches the station safely, the station's astronauts will use a robotic arm to bring the commercial spaceship in for berthing, and then unload the non-essential cargo that's aboard.

A couple of weeks later, Dragon would be sent back down to a Pacific Ocean splashdown.

A success during this first berthing attempt would open the way for SpaceX to start regular robotic resupply missions to the space station under the terms of a $1.6 billion NASA contract. It also could help pave the way for Dragon to ferry Americans to and from the space station in three to five years, depending on further NASA funding. 

Since the last space shuttle left the station last July, Americans can travel into orbit only as passengers aboard Russian spacecraft, at a cost of about $60 million a seat.

More about SpaceX and the commercial space race:

• Private spaceship launch on the horizon
  
• SpaceX has a lofty goal: Help save humanity
• Next steps in the new space race

Last updated 3:25 p.m. ET. Tip o' the log to NBC News' Cape Canaveral correspondent, Jay Barbree.

 Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

NASA / JPL-Caltech / SSI

Two of Saturn's more than 60 moons join the ringed planet in this scene, captured by the Cassini orbiter on Jan. 19 and released on April 30. Tethys appears as a small white dot above the rings on the far left of the image. Enceladus appears as a smaller bright speck beside the planet. The rings cast wide shadows on the planet's southern latitudes.

Two of Saturn's moons are dwarfed by the giant planet and its rings in this family portrait from the Cassini spacecraft, which will mark its eighth year in Saturnian orbit in July. This image was put out by the Cassini imaging team on Monday, just a little too late to make our Top 20 roundup for the Month in Space Pictures — but it's worth passing along as a bonus prize.

You can see 660-mile-wide Tethys as a white dot toward the left edge of the image, and 313-mile-wide Enceladus as a smaller bright speck beside the planet. Tethys is thought to be composed mostly of water ice with a bit of rock mixed in, while Enceladus is a very special case: Cassini has repeatedly documented geysers of water ice spewing from fissures in that moon's surface — suggesting that liquid water and perhaps even living things may lie beneath. It'll be up to a future probe to plumb the mysteries of Enceladus more deeply.

Saturn's rings are seen nearly edge-on, and in this picture they're casting wide, curved shadows on Saturn's southern hemisphere. Bad Astronomy's Phil Plait says he can't help noticing the thin white ribbon of clouds stretching across the planet's northern hemisphere. Those may be the remnants of a monster storm that wrapped itself around the globe for months, starting in late 2010. "Our gas giants don't screw around," he writes. "When they do something, they do it big."

And when we do the Month in Space Pictures slideshow, we do it big as well. Click on the image below to see some of the best out-of-this-world views from the month of April. You'll find shots from the final flights of the shuttles Discovery and Enterprise, photos of weird phenomena on Mars and Uranus, and even a UFO (Galaxy, that is). If you want to find out more about the stories behind the pictures, leave a comment and I'll try to point you in the right direction.

Slideshow: Month in Space: A blaze of glory

NASA/SDO/AIA

Click through a solar eruption, the final odyssey of the shuttle Discovery and other outer-space highlights from April 2012.

Launch slideshow

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Exploratorium

Paul Doherty, a senior staff scientist at the Exploratorium, Paul Doherty, sets up telescopes for observations of the 2001 total solar eclipse in Zambia. This year features an annular solar eclipse in May, a transit of Venus in June, and a total solar eclipse in November.

Over the next several weeks, skywatchers will thrill to a couple of astronomical wonders playing out in daytime skies: a solar eclipse on May 20 — and then, on June 5, a "micro-eclipse" of the sun that involves the planet Venus.

As senior staff scientist at San Francisco's Exploratorium, Paul Doherty will be keeping a careful eye on both of those wonders (with appropriate eye protection, of course). He'll let you in on his eclipse-chasing secrets on Wednesday night during a "Virtually Speaking Science" chat on BlogTalkRadio and in the Second Life virtual world. I'll be the host for the hourlong show, starting at 9 p.m. (6 p.m. PT/SLT).

Doherty says the solar eclipse and the micro-eclipse will be well worth chasing.

"By all means, go out of your way to see 'em," he told me this week. "They are rare events ... You'll have things to talk about for years after."

Each event offers a special kind of rarity: This month's eclipse is of the annular variety, which means that the moon's disk isn't quite big enough to cover the sun completely. At its darkest, the moon's black circle will be surrounded by a spectacular "ring of fire." That sight can be seen only along a narrow track running along Earth's surface, from China across the Pacific to the western United States. But a partial solar eclipse will be visible across a much wider swath of territory. It'll take about three and a half hours for the moon's umbral shadow to race across Earth's surface, from 6:06 to 9:39 p.m. ET.

Next month's micro-eclipse, more formally known as a transit of Venus, is even rarer. The planet's tiny black disk will march across the sun over the course of several hours (roughly from 6 p.m. ET June 5 to 12:50 a.m. ET June 6). Most of the world will get in on at least part of the show, but the best viewing will be had once again from the Asia-Pacific region. This will be the last transit of Venus most of us will ever get a chance to see: The next one is due in the year 2117.

Even if you're not in the viewing zone, or the skies are cloudy, you can still get in on these events via online presentations that will be sponsored by a variety of organizations — including the Exploratorium, of course. The combination museum and science center is planning a webcast of the transit as well as a Second Life teach-in timed to coincide with the annular eclipse. Doherty will be in on all the action — in Nevada for the eclipse, and at San Francisco HQ for the transit.

Jeroen Frans

Second Life residents watch a virtual presentation about eclipses on Exploratorium Island, in an image by Jeroen Frans (a.k.a. Frans Charming) of VesuviusGroup.com.

Over the past 40 years, Doherty has been chasing astronomical events in locales ranging from Cape Cod to Zaire. In this first of two postings about the coming attractions, Doherty discusses the appeal of eclipses and transits, plus a little bit of the science behind them. Here's an edited transcript of the Q&A:

Cosmic Log: You've been in on a number of solar eclipses in your time — what is it that draws someone to become an eclipse-chaser? A lot of people talk about how sun-observing satellites have come so far that eclipses aren't as crucial for scientific observations as they used to be. So what's the appeal?

Paul Doherty: It's certainly true that an eclipse is not a scientifically significant as it was a century ago, but I will tell you there's something special about the experience of an eclipse — even a partial eclipse. You'll be outdoors, looking around, and you'll notice that the light is getting very strange. There's a beautiful clear sky, and it starts to get dim. Your body knows that something really different is happening. It's great for people to know what's causing that feeling: The moon is blocking the sun. (But don't look at it directly with your unprotected eyes.)

Then, for totality, you have the experience of seeing a clear sky go dark at midday, so that the brightest planets and stars are visible. You see that black disk where the sun should be, surrounded by bright rays like big fat spider legs of white around the sun. That will set the hair on your back standing up, even if you're a scientist and you know what this is. It is just so awesome to see it.

So I look at modern eclipses as places for people to come in contact with a great event in our solar system, and it shouldn't be missed.

Q: Do you find that it's an inspirational experience? Do eclipse-chasers go on to "harder drugs" in astronomy?

A: I've met so many eclipse-chasers who are already into the harder stuff. You just can't tell which came first. But I'm sure that the sight of a total eclipse just inspires them. I've seen eight solar eclipses myself, and I keep running across the same people. I know that they're inspired to really take time out of their lives, and take money out of their bank accounts, and invest it in these few minutes of a great experience, surrounded by an hour of interesting shading in the sky, surrounded by days of travel to wonderful places on Earth and meeting people with the same passion they have.

Q: What are the differences between a total solar eclipse like the one in November, and an annular eclipse like the one this month?

A: The moon is in an elliptical orbit around the earth. When the moon is at its farthest point from the earth, its angular size in the sky is a little smaller, and when it's close to the earth, it's a little bigger. Also, the earth is in an elliptical orbit around the sun. It gets smaller and bigger. When the moon is farthest from the earth, it's small enough in the sky that it cannot totally block the bright part of the surface of the sun called the photosphere. That's where the bright light comes from on the sun. At that point, the rim of the photosphere shines around the edge of the moon. That light is so bright that it can damage your eyes if you look at it without eye protection. It overwhelms the dim light coming from the chromosphere and the corona of the sun.

But during a total solar eclipse, the moon is big enough in angular size to block out the photosphere completely, and with your naked eye you can see this million-degree gas glowing in the corona, like rays reaching out quite a ways from the sun. You can see the red chromosphere quite near the edge of the moon. You can even see prominences reaching out from the sun and moving during the course of the eclipse. The total eclipse offers many more things to see than the annular eclipse does.

However, an annular eclipse provides you with a bright circle of the sun. Let's say that sunlight is streaming through the leaves of a tree, and you look at the ground. Normally, you'd see round circles of light at your feet. During an annular eclipse, those all become the letter "O." That is really something, to look at the ground underneath a tree and see it covered with bright Cheerios.

If you're not on the center line of annularity, and it's a partial solar eclipse, then those images become the letter "D," or a really nice letter "C."

There are more total solar eclipses than there are annular eclipses, because it takes this special combination of the moon being a little farther away from the earth than average, and the sun a little closer, to create this annular eclipse opportunity.

Q: It seems as if people in the know are getting as excited about next month's transit of Venus as they are about the eclipse. Why is that?

A: Well, the transit of Venus is a much rarer occurrence. And it is kind of a micro-eclipse. Venus is one-thirtieth the diameter of the sun in angular size, and it's moving across the sun's disk in this stately procession that lasts six hours. It happens in this amazing pattern: There'll be one transit, and then eight years later there'll be another one, and then it's 121.5 years, then eight years, then 105.5 years. It's a really weird pattern.

You wouldn't even notice a transit was happening unless someone told you. The light on the ground is not going to change. You're not going to see anything. But it's different if you know it's happening, like Jeremiah Horrocks did in 1639. He noted that Johannes Kepler, his hero, missed the calculation that Venus was going to transit the face of the sun. Horrocks actually set up a telescope to project the sun's image into his darkened room, and became the first person ever to see a transit of Venus and record it.

Now, knowing what we do, we can tell you that on this day, at this time, if you project an image of the sun safely or use a sun-viewing filter, you can see this tiny black disk going across the face of the sun. That's interesting — but what's really interesting is that in 1761, they used the transit observations to measure the size of the solar system. Good old Halley, of Halley's Comet, figured out how to do that. They did it kind of roughly, during transits.

Q: And even today, astronomers are using alien transits to learn about new planets beyond our solar system...

A: That's right. In 1761, a Russian astronomer named Mikhail Lomonosov discovered the atmosphere of Venus during a transit. He noted that as Venus approached first contact with the sun's disk, it was completely surrounded by a bright glow, which was the sunlight being refracted by Venus' atmosphere and being sent to Earth. That's how scientists first detected Venus' atmosphere. And during the transit eight years ago, scientists used the sunlight going through the atmosphere of Venus to measure its composition.

We're doing that exact same thing with exoplanets. We're studying the light going through the atmosphere of those exoplanets, and we've actually found the constituents of the atmospheres of some of those exoplanets. They've found water vapor, and carbon dioxide, and sodium gas. We're using the very same techniques we used on Venus to study the air of exoplanets.

On Wednesday, we'll talk about some of the best places in America to see this month's annular eclipse, how to pick out an advantageous viewing spot near you, and how to make sure you see the eclipse and the transit safely. Then, be sure to tune in "Virtually Speaking Science" on BlogTalkRadio or in Second Life — and bring lots of questions. Paul Doherty (a.k.a. Patio Plasma) and I will be at the StellaNova Small Auditorium, courtesy of the Meta Institute for Computational Astrophysics, starting at 9 p.m. ET (6 p.m. PT/SLT) on Wednesday. If you miss the live event, don't worry: It'll be archived by "Virtually Speaking" on BlogTalkRadio as well as iTunes.

On Friday, head on over to the Cosmic Log Facebook page for our weekly "Where in the Cosmos" picture puzzle. If you're the first to solve the riddle, you'll be eligible to receive a pair of sun-viewing safety glasses for this month's eclipse and next month's transit. In the meantime, check out these podcasts from previous episodes of "Virtually Speaking Science," plus links to eclipse-related resources:

• Veronica Ann Zabala-Aliberto on spaceflight and Yuri's Night
• JPL's Dave Beaty on the search for life on Mars
• Shawn Lawrence Otto on science and politics
• Ig Nobel impresario Marc Abrahams on silly science
• Rocket scientist Robert Zubrin on Mars exploration
• Propulsion expert Marc Millis on interstellar spaceflight
• Sean Carroll on the puzzling frontiers of physics
• Rand Simberg on the private-enterprise vision for spaceflight
• Martin Hoffert on the future of energy policy
• George Djorgovski on science in virtual worlds
• Alan Stern on suborbital research and NASA's mission to Pluto
• Col. 'Coyote' Smith on the outlook for space solar power
• Tim Pickens on rocket ventures and the Google Lunar X Prize

More about eclipses:

• Interactive graphic: What causes a solar eclipse?
• 12 must-see skywatching events in 2012
• All about solar eclipses on msnbc.com

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.