Virgin Galactic's SpaceShipTwo rocket plane lit up its engine for the first time in flight on Monday, taking a giant supersonic leap toward outer space.

The crucial 16-second blast took place at about 7:50 a.m. PT (10:50 a.m. ET), high above California's Mojave Air and Space Port. Virgin Group's billionaire founder, Richard Branson, was on hand to watch the proceedings.

"Today was the most significant day in the program," Branson told NBC News afterward. "I think that for those people who have been good enough to stick with us for the last eight years, who signed up early on, their time to become astronauts is very soon now. ... We'll soon be able to make their dreams come true."

Branson wasn't the only one watching: Rocket aficionados flocked to viewing areas near the airport to see the blastoff. Until Monday, Mojave-based Scaled Composites, which is building and testing the plane for Virgin Galactic's eventual use, had tested SpaceShipTwo only by dropping it from its WhiteKnightTwo carrier airplane and having its pilots guide the plane back through unpowered glides back to the runway. The engine, powered by a rubber-based solid fuel and nitrous oxide, had been fired only on the ground.

Monday's test was radically different: WhiteKnightTwo released SpaceShipTwo from its traditional drop zone, at an altitude of around 47,000 feet. But after the rocket plane glides clear from the mothership, its pilot lit up the engine and pointed SpaceShipTwo upward into the sky, reaching a maximum height of 56,200 feet. The plane coasted back to a landing back at the Mojave airport, about 13 minutes after blastoff.

Test pilots Mark Stucky and Mike Alsbury were at SpaceShipTwo's controls for Monday's flight, Virgin Galactic said. Afterward, the company said in a tweet that the pilots confirmed "SpaceShipTwo exceeded the speed of sound on today's flight!" The reported maximum velocity was Mach 1.2.

Virgin

SpaceShipTwo fires up its rocket engine for the first time in flight on Monday.

MarsScientific.com / Clay Center Observatory

A 16-second rocket blast sends SpaceShipTwo toward the heavens.

Virgin Galactic via W. Christine Choi

A boom camera on Virgin Galactic's SpaceShipTwo plane shows the rocket engine firing.

George Whitesides, Virgin Galactic's president and CEO, said in a news release that the flight test "went as planned, with the expected burn duration, good engine performance and solid vehicle handling qualities throughout."

Eventually, SpaceShipTwo could break the space barrier as well as the sound barrier — just as its predecessor, SpaceShipOne, did in 2004. When the single-piloted SpaceShipOne made repeated flights beyond an altitude of 100 kilometers (62 miles), which is the internationally accepted boundary of outer space, it won the $10 million Ansari X Prize for private spaceflight. Ever since then, Virgin Galactic has been funding the multimillion-dollar development effort to create a fleet of passenger space planes.

In the grand scheme of things, suborbital spaceflight isn't exactly new: The U.S. Air Force's X-15 rocket plane blazed that trail to manned spaceflight a half-century ago. The new twist is that it's being done by private companies rather than government programs. 

Scaled and Virgin Galactic have mapped out a series of flight tests that would gradually push the envelope, potentially leading to suborbital spaceflights over California's Mojave Desert by the end of this year. Virgin Galactic's goal is to begin passenger service, for tourists as well as researchers, at New Mexico's Spaceport America as early as next year. More than 500 people — including celebrities such as Ashton Kutcher — have already put down money for a $200,000 ride.

The six-passenger, two-pilot plane is designed to give riders a commanding view of the curving Earth beneath the black sky of space, a few minutes of free-floating weightlessness, and a roller coaster ride back down to Virgin Galactic's spaceport. Other companies — including XCOR Aerospace and Blue Origin — are planning to get into the suborbital space passenger business as well, but if SpaceShipTwo's flight tests go well, Virgin Galactic is likely to become the market leader.

Branson has said he and his family would be among the first to fill SpaceShipTwo's passenger seats.

"Like our hundreds of customers from around the world, my children and I cannot wait to get on board this fantastic vehicle for our own trip to space and am delighted that today's milestone brings that day much closer," he wrote in a blog post.

Slideshow: The making of SpaceShipTwo

Click through scenes from the construction of Virgin Galactic's suborbital passenger spaceship.

Launch slideshow

More about SpaceShipTwo:

• Virgin billionaire can't wait for space ride
• Tom Cruise might be up for space
• Cosmic Log archive on SpaceShipTwo

Alan Boyle is NBCNews.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. To keep up with Cosmic Log and the rest of NBCNews.com's science and space coverage, sign up for the Tech & Science newsletter, delivered to your email in-box. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

This story was originally published on Mon Apr 29, 2013 10:29 AM EDT

Droplets of condensation may make a cold can of beer look more appealing on a hot day, but they're also making that frosty brew warm up faster. So here's some news you can use: If it's hot and humid, put a cover over your can of cold beverage. And if you want to warm up a frozen can quickly, don't bake it. Steam it.

That's exactly what University of Washington researchers did in a series of experiments to show how the warming power of condensation applies to issues ranging from colder beer to hotter climates.

The beer-can study, published in the April issue of Physics Today, began a couple of years ago when UW atmospheric scientist Dale Durran was looking for a way to explain how condensation produced heat as the flip side of evaporative cooling. The cooling effect is well-known — we feel it when sweat evaporates to cool us off in the summer time, or when we turn on a mist cooler. But the flip side of the effect is less widely understood.

Durran figured out that the condensation on a cold aluminum can might serve as a handy illustration. He did a quick back-of-the-napkin calculation, and found that the heat released by water just 100 microns (four thousandths of an inch) thick should heat its contents by 9 degrees Fahrenheit (5 degrees Celsius).

"I was surprised to think that such a tiny film of water would cause that much warming," Durran said in a UW news release.

He recruited a fellow atmospheric scientist at UW, Dargan Frierson, to conduct the initial experiment ... in Frierson's basement bathroom. First, they set a can of beverage on the toilet tank and warmed it up with a space heater. Then they took another can, turned on the shower and let the bathroom get nice and steamy. Each time they ran the experiment, the researchers stuck a thermometer through the can's pop-top opening and watched the temperature rise over the course of 15 minutes.

Mariusz Kaldon

Droplets of condensation on a chilly can are a signal that the temperature inside is rising.

Frierson said conditions got a little sticky in the steamed-up bathroom. "I think that's the most uncomfortable my research has ever made me — but it's all for science," he told NBC News.

Even though the air temperature was the same in both cases, the liquid in the steamed-up can warmed up twice as fast. The researchers followed up on the basement-bathroom findings with more rigorous lab experiments. Every time, the cans warmed up more quickly in more humid conditions.

The researchers even charted how quickly 12-ounce aluminum cans of chilled liquid should warm up, depending on different levels of temperature and humidity. For example, in five minutes, the can should get 6 degrees F (3 degrees C) warmer due to condensation amid New Orleans' typical summer conditions. The equivalent warm-up factor would be 3.5 degrees F (2 degrees C) in New York, and 2 degrees F (1 degree C) in Seattle. But in Dhahran, a Saudi city that ranks among the hottest, stickiest places in the world, the can would get about 14 degrees F (8 degrees C) warmer in five minutes.

That's why covering a cold can is a such a good idea on a steamy-hot summer day. "Probably the most important thing a beer koozie does is not simply insulate the can, but keep condensation from forming on the outside of it," Durran said.

The effects of condensation and evaporation are well-known to climatologists, but Durran and Frierson say the beer-can experiments can give the general public a better understanding of atmospheric dynamics.

"Condensation as a heat source is just tremendously important," Frierson said. "It's really like the gasoline that powers hurricanes, thunderstorms and tornadoes."

Some climate models suggest that there could be 25 percent more humidity in the atmosphere by the end of the 21st century, and that could lead to more bouts of extreme weather in the decades to come.

"We want people to appreciate how powerful this effect is," Durran told NBC News. "A very thin film around the can makes a big difference in the temperature of its contents, and that just makes you appreciate the importance of that same heating effect in our atmosphere."

Here's how to run the experiment described in the YouTube video from University of Washington Department of Atmospheric Sciences Outreach:

1. Freeze two cans of your favorite beverage. This should take roughly seven hours, depending on your freezer.
2. Fifteen minutes before taking out the cans, preheat oven to 250 degrees F and start boiling water in a pot. Place a cookie rack on top of pot.
3. Take the cans out of freezer. Place one in the preheated oven. and one over the boiling pot. 
4. Start timer for 10 minutes. 
5. After 10 minutes, carefully remove cans from oven and pot.
6. Crack open both cans and pour into separate glasses.
7. Take a photo/video of the two cans and glasses, go to the UW YouTube page, and post a video response.

More beer-can science:

• Tiny sip of beer can produce burst of pleasure
• Study explains the science of a beer buzz
• Scientists study how beer goes bad

Update for 9:30 p.m. ET April 26: Would wiping off the drops of condensation keep your drink cooler? Sorry, says UW spokeswoman Hannah Hickey. "That will only make your drink even warmer," she writes in a Twitter update.

Update for 2:25 p.m. ET April 27: Some commenters are wondering why there's so much fuss over a relatively simple concept. The point of the exercise wasn't really to break new ground in atmospheric physics (or in summertime beverage consumption), but "to improve our intuition about the power of condensational heating" — which is a huge factor in climate dynamics. Durran explained further in a comment below, and I'm providing an extended version of his comments here to give them a little more visibility:

"In my class, students definitely need to know how condensation causes heating. Here's how. There are bonds that link water molecules together into a crystal lattice to form ice. It takes heat (energy) to break a few of those bonds and turn ice to liquid water. To evaporate the liquid water, the rest of the bonds between molecules need to be broken, which takes a lot more heat. Once all the bonds are broken, the liquid is converted to water vapor, an invisible gas.

"This processes reverses when water vapor is cooled enough to condense as liquid water. Bonds between molecules re-form, and the heat it took to originally break them is released into the surroundings.

"The reason we make a big deal about the power of condensational heating is that it does amazing things in the atmosphere, such as powering the updrafts in thunderstorms. The rising cloud-filled updrafts in the video linked below ascend like hot-air balloons because they are warmed, not by burning a fuel like propane, but by the heat released as water vapor condenses.

"Here's the video link: http://www.youtube.com/watch?v=GVIwDoogncQ

"Such a visualization might help people understand some of the applications. (Only the last half of the Physics Today article was about the beer can heating.)"

Durran and Frierson are the authors of "Condensation, Atmospheric Motion, and Cold Beer" in Physics Today. Supplemental experiments are described in "An Experiment Uses Cold Beverages to Demonstrate the Warming Power of Latent Heat." Lab experiments were performed by Stella Choi and Steven Brey. Galen Richards and Jaycyl Golding, high school students serving as Pacific Science Center Discovery Corps interns, worked on earlier versions of the experiments. Instrument makers Allen Hart and Steven Domonkos built experimental apparatuses. Funding was provided by National Science Foundation grants AGS-0846641 and AGS-1138977.

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Slideshow: Our fragile Earth

AFP - Getty Images

Images from outer space highlight the fragility — and the resilience — of our beautiful blue planet.

Launch slideshow

Technological advances aren't always kind to Mother Earth — witness the impact of nuclear waste, industrial emissions and plastic bottles — but high-tech environmental monitoring systems are also helping us get a handle on the state of our planet. It's good to remember that as Earth Week draws to a close.

Just in the past couple of years, NASA has added to the nation's fleet of Earth-observing satellites. In 2011, the $1.5 billion Suomi NPP satellite went into orbit, blazing a trail for a new generation of planet-watchers that can provide data about extreme weather as well as environmental indicators. Suomi's five sensor systems are tracking atmospheric and sea surface temperatures, biological productivity, ozone levels and much, much more.

This February, the $855 million Landsat Data Continuity Mission finally got off the ground, opening a new chapter for the 41-year-old Landsat Earth-monitoring program. LDCM will monitor surface temperatures around the planet and generate 400 images a day in visible and infrared wavelengths. Multi-wavelength observation is a key technology for monitoring the planet's health, because thermal infrared readings can tell you how vegetation is faring, how much heat the world's cities are putting out, and how the world is coping with climate change.

"If you want to deal with climate, you need observations, instead of just talking about belief or simulations," Compton Tucker, senior biospheric scientist at NASA's Goddard Space Flight Center, told NBC News.

Even Earth's gravity field can provide insights into how the planet is changing: Readings from the Gravity Recovery and Climate Experiment, or GRACE, have traced the loss of ice from the world's glaciers and ice caps by measuring subtle changes in our planet's distribution of mass. "It's really a phenomenal source of information to study water on the surface," Tucker said. 

For decades, observations from outer space — including data from NASA satellites such as Terra and Aqua, as well as the National Oceanic and Atmospheric Administration's weather satellites and the Landsat constellation — have been helping scientists understand what's happening to our environment.

Suomi NPP and LDCM are continuing that legacy, but there are still concerns about the future: Last year, the National Research Council voiced grave concerns about America's aging Earth-observing system, saying that the projected loss of satellite capability "will have profound consequences on science and society, from weather forecasting to responding to natural hazards."

The federal government's money troubles could trigger more immediate cutbacks in the nation's Earth-watching capability. It may well turn out that the biggest obstacles to understanding what ails our planet aren't natural phenomena, but problems of our own making.

More about high-tech environmental monitoring:

• How's Earth's health? New network to keep tabs
• Landsat celebrates 40 years of watching our planet
• How satellites are saving the world

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

MarsScientific.com / Clay Center Observatory

Cold oxidizer streams from the back of SpaceShipTwo's engine during an unpowered test flight on April 12. Richard Branson, the billionaire founder of Virgin Galactic, says the rocket plane could go supersonic when its engine is lit up for the first time in flight, as early as Monday.

Virgin Galactic's billionaire founder, Richard Branson, says his company is planning to fire up SpaceShipTwo's rocket engine for the first time in flight on Monday — a "historic" blast that is expected to send the space plane supersonic.

"We're hoping to break the sound barrier," Branson told the Las Vegas Sun. "That's planned Monday. It will be a historic day. This is going to be Virgin Galactic's year. We'll break the sound barrier Monday, and from there, we build up through the rest of the year, finally going into space near the end of the year. I'll be on the first official flight, which we look to have in the first quarter of next year. We're doing a number of test flights into space first."

Branson made his comments on Monday during a visit to kick off Virgin America's airline service to Las Vegas. In just one paragraph, the British entrepreneur and adventurer capped off weeks of rumors and laid out a new timeline for starting up passenger flights to outer space.

SpaceShipTwo builds on the heritage of SpaceShipOne, which powered its pilots beyond the 100-kilometer (62-mile) altitude mark in 2004 to win the $10 million Ansari X Prize for private-sector spaceflight. SpaceShipOne is now hanging in the Smithsonian, but SpaceShipTwo has been under development for years at Scaled Composites in Mojave, Calif. Scaled has been conducting a series of unpowered tests at the Mojave Air and Space Port. During an April 12 "cold flow" flight test, Scaled's pilots rehearsed every step for a powered flight, short of lighting up the hybrid rocket engine.

So far, SpaceShipTwo has been attached to the belly of its WhiteKnightTwo mothership, carried up to altitudes of around 50,000 feet and then dropped into the air to make a glider-like landing. During powered tests, SpaceShipTwo's engine will be lit up after the drop. The rocket plane will make a spectacular blast into the heavens and then glide back to the runway.

"We’ve experienced about a year’s worth of vertical flight tests and captive-carry flight tests by a number of tenants, and now we’re entering the phase of manned research flights," Stuart Witt, CEO of the Mojave Air and Space Port, told NBC News. "We’re excited about that: The industry has been waiting for this for a long time – since 2004."

Virgin Galactic's CEO and president, George Whitesides, stressed that the test schedule was dependent on several factors, including the weather. He said the first rocket-powered test could easily slip to a later time.

Like Branson, Whitesides said the first powered flight, known as PF01, would be merely the first step in the next phase of testing. "PF01 will be the start of a series of increasingly longer-duration burns (PF02, PF03, etc.) that should lead us to space altitude before the end of the year and commercial ops start soon after that," he said in an email to NBC News.

Virgin Galactic plans to conduct commercial spaceflights from Spaceport America in New Mexico, with passengers charged $200,000 for a ride. More than 500 customers have already put money down for flights. The passengers would experience breathtaking views of the curving Earth beneath the black sky of space, go weightless for a few minutes and then strap themselves back in for a powerful plunge back to the runway.

The first supersonic flight of a new spaceship isn't always auspicious: When SpaceShipOne came in for a landing in Mojave after breaking the sound barrier for the first time on Dec. 17, 2003, its left landing gear collapsed and the plane ran off the runway. Fortunately, no major damage was done, and pilot Brian Binnie was unhurt. Binnie went on to fly SpaceShipOne into space on Oct. 4, 2004, to win the $10 million prize.

Blue Origin, a rocket venture backed by Amazon.com billionaire Jeff Bezos, put its prototype spacecraft through its first unmanned supersonic flight at a Texas rocket range in August 2011 — but the company said the craft had to be destroyed when it experienced a "flight instability" at an altitude of 45,000 feet. Blue Origin recovered from that setback and is continuing to work on suborbital as well as orbital spacecraft.

Slideshow: The making of SpaceShipTwo

Click through scenes from the construction of Virgin Galactic's suborbital passenger spaceship.

Launch slideshow

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email inbox every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Takeshi Inomata

Workers stand on Platform A-24 at the Ceibal archaeological site in Guatemala. Archaeologists say the dig revealed the oldest monumental construction in the Maya lowlands.

Archaeologists say that ceremonial structures unearthed in Guatemala are centuries older than they expected — and that the findings point to new theories for the rise of Maya culture.

"The origin of Maya civilization was more complex than previously thought," the University of Arizona's Takeshi Inomata, lead researcher for a study appearing in this week's issue of the journal Science, told reporters on Thursday. Even though all this happened 3,000 years ago, the findings could provide fresh insights about social change in general, he said.

The Maya had their heyday in Mexico and Central America between the year 250 and 900, but the roots of their culture go much farther back. There are several schools of thought about how their distinctive culture arose: Some archaeologists say the central features of Maya cultural life, including grand ceremonies centered on broad plazas and pyramids, were borrowed from Mexico's older Olmec civilization. Others say those features arose internally, without much outside influence.

Inomata said the excavations at Ceibal, in Guatemala's Maya lowlands, suggest a more complicated scenario. Over the course of seven years, he and his colleagues dug down more than 50 feet, analyzed the layers of sediment, and did scores of radiocarbon-dating tests to trace the evolution of Ceibal's structures. They concluded that Ceibal's Maya rulers started building ceremonial plazas and platforms around 1000 B.C., and had turned those structures into a central pyramid and plaza by 800 B.C. 

That would mean Ceibal's residents were developing the architectural and religious hallmarks of Maya society before the first appearance of those hallmarks in Olmec society, at La Venta, hundreds of miles away on Mexico's Gulf Coast. La Venta's ceremonial structures have been dated to about 800 B.C.

Science / AAAS

Ceibal lies in Guatemala's Maya lowlands. The Olmec centers of San Lorenzo and La Venta were hundreds of miles away, in Mexico. Researchers say Ceibal also was influenced by other communities in central Chiapas and along the Pacific coast.

Other Maya settlements were building such structures around that same time, although they weren't as developed as Ceibal's. A wide spectrum of Mesoamerican communities — for example, settlements in central Chiapas and those on the southern Pacific coast — may have had a lot of important interactions with Ceibal and other communities in the Maya lowland during this period, Inomata said.

He stressed that the Olmec almost certainly influenced Maya culture during the centuries that predated Ceibal's rise. For example, there's evidence that an Olmec center near San Lorenzo was dominant well before Ceibal's residents began building their ritual structurs. However, Inomata said, "San Lorenzo didn't have the kind of ceremonial complexes that we're talking about."

The period from 1000 and 800 B.C. appears to have been a key turning point for Maya culture. There may have been a "power vacuum" between the fall of San Lorenzo and the rise of La Venta that gave early Maya communities the opportunity to experiment and develop cultural innovations, Inomata said. "We are looking at major change in this period, and that happened really in the absence of a very strong Olmec center," he told reporters.

The construction of Ceibal's ceremonial complexes would have required the participation of the whole community, said the University of Arizona's Daniela Triadan, who is a co-author of the Science paper as well as Inomata's wife. "Some people might already have had a special position in the community, and they were most certainly people with specialized ritual knowledge. This indicates that the transition from a mobile hunter-gatherer and horticultural lifestyle to permanently settled agriculturalists was rapid," she said.

What drove that rapid change? The research team is still looking into potential environmental factors, but Inomata speculated that the cultivation of maize — that is, corn — may have been decisive. "There may have been a major increase in maize production, which may have been a threshold in terms of the development of cultural elements," he said.

"This is not just a study about this specific civilization," Inomata told reporters. "We also want to think about how human societies change, and how human civilization developed. What we are seeing here is that major renovation and change can happen through the interaction of various groups. It doesn't have to come from powerful, major political centers. That's one important implication that we are getting."

More about the Olmec and the Maya:

• Olmec influence stretched hundreds of miles
• Maya doom teaches climate lesson
• Cosmic Log archive on Maya culture

In addition to Inomata and Triadan, the authors of "Early Ceremonial Constructions at Ceibal, Guatemala, and the Origins of Lowland Maya Civilization" include Kazuo Aoyama, Victor Castillo and Hitoshi Yonenobu.

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA / JPL / Cornell

When some people look at this nine-year-old picture from NASA's Spirit rover, they see a graphic depiction of manhood. Actually, it's standard operating procedure for making a turn on Mars.

Some Mars maniacs just won't grow up: A picture of the track patterns left behind by the Mars rovers' standard turning maneuver has drawn giggles and gasps — merely because it looks like a penis scrawled on the Red Planet.

"The rude drawing has emerged in a series of images taken by one of its rover machines. ... The latest pictures beamed back from one of the rovers show signs that the project's controllers have started to get a bit bored," The Sun, a British tabloid, reported on Wednesday.

Even Sarcastic Rover, one of Twitter's top parody personas, got into the act: "Since everyone's asking, let me just say that some other robot did this ... definitely not me," it tweeted.

The jibes from Sarcastic Rover and The Sun, and tons more like them, were sparked by a Reddit forum's discovery of the picture the day before. But this picture isn't the product of a bored (or filthy-minded) rover driver, and it wasn't beamed down recently. It's part of a classic nine-year-old panorama from NASA's Spirit rover, looking back toward its landing platform. (You can actually see the platform in the high-resolution version of the panorama.)

This type of rover wheel-track pattern, which could euphemistically be called "a bat and two balls," has been left on Mars many times, not only by Spirit (which gave up the ghost in 2010 or so), but also by Opportunity (which is still going strong more than nine years after landing on Mars) and Curiosity (which landed last year).

All those rovers have six wheels, three on each side, and they leave behind two parallel tracks when they're traveling in a straight line. When the rover has to make a turn, the wheels rotate in place to put the robot in the desired direction for the next leg of its trek. If the turn is significant enough, you get a nice set of circles at the end of a pair of parallel tracks.

Got it? Now we can move on — for instance, to lewd pictures from the Hubble Space Telescope.

NASA / ESA / STScI / AURA / La Plata Obs.

A sub-cloud of dust in the Carina Nebula displays what some have called "the cosmic finger of friendship."

More tracks from the Red Planet:

• That's one small step ... on Mars?
• Curiosity leaves tracks in Morse code
• 3-D adds depth to tracks on Mars

Tip o' the Log to Jia-Rui Cook at NASA's Jet Propulsion Laboratory for finding the original Spirit panorama from Mars.

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

What will the far future look like? For actor Will Smith and his son Jaden, the next generation could mark a "tipping point" for the environment. For futurist Ray Kurzweil, solar power is the solution to our energy ills. But for a look at the really far future, turn to Elon Musk, the billionaire founder of SpaceX and Tesla Motors. He's already thinking about spreading out from Earth to other planets — and engaging the warp drive to get to other star systems.

"There's some potential, even though it sounds science-fictiony, for warp drive to work," Musk said on Tuesday during a Google+ Hangout to publicize "After Earth," Smith's upcoming movie. "Technically, to warp space such that you're traveling at the speed of light, but you've warped space so that space is actually traveling."

Musk was referring to recent studies updating the "Star Trek" conception of warp travel, in which a whole region of the space-time continuum zips along at faster-than-light speeds. Researchers at NASA's Johnson Space Center say the idea isn't as crazy as it sounds, and they're trying to create space-time perturbations on a microscopic scale.

Even NASA Administrator Charles Bolden is on board: "One of these days, we want to get to warp speed," he said last September. "We want to go faster than the speed of light, and we don't want to stop at Mars."

Musk, however, sees Mars as a key stop on the path to turning humanity into a multiplanet species. "Either we're a spacefaring civilization, or we're going to be bound to Earth until some eventual extinction event," he said Tuesday.

All this meshes with the plot of "After Earth," in which Will and Jaden Smith play a father and son who find themselves back on Earth a millennium after cataclysmic events forced humanity to find refuge in a distant star system. The filmmakers organized the Hangout to give the Smiths as well as Musk, Kurzweil and environmentalist Alexandra Cousteau a chance to reflect on humanity's future. (It was also a chance to give the movie some publicity on the day "after Earth Day.")

You can watch the whole Hangout on YouTube, but here are some highlights:

Will Smith on working with his son on the movie: "It was wonderful for the two of us to become environmentally educated together. ... The huge question of water came up: the idea that today it's oil that we're willing to go to war over, and at some point in the future, it's going to be water."

Jaden Smith, 14, on the challenges facing the next generation: "Our world is going to get to a tipping point ... if we want to stop that, then my generation would have to almost become obsessed with it, and say we're stopping everything that we're doing wrong right now: no more plastic, only reusable sources, only solar power."

Alexandra Cousteau, granddaughter of Jacques-Yves Cousteau: "We're on the knife's edge of either protecting this place where we live, or losing an enormous amount of it. But I have to say I completely agree with Jaden, in that this generation has an extraordinary opportunity to use technology that we've never had before ... to actually take control of our use of resources."

Ray Kurzweil, Google's director of engineering, on the promise of solar power: "The total solar energy in the world is on an exponential rise. It's doubling every two years. ... Within 15 years we could meet all of our energy needs with solar. Solar is actually cost-comparative with other forms of energy like fossil fuels without any subsidies in different regions of the world."

More thoughts on the future: 

• Engineering's greatest challenge: our survival
• Take a test drive through the next century
• The biggest challenge for interstellar flight? Us

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

M. Showalter / NASA / ESA

An image from the Hubble Space Telescope shows Pluto and its largest moon, Charon, surrounded by four smaller moons. Astronomers have proposed naming P4 and P5 after Vulcan and Cerberus.

Astronomers have decided to go with the people's choice and propose Vulcan and Cerberus (or Kerberos) as the names for Pluto's tiniest known moons, one of the discovery team's leaders said Tuesday. Vulcan bubbled up to the top of the list in a non-binding "Pluto Rocks" contest in February, thanks in part to a strong endorsement from "Star Trek" captain William Shatner. The International Astronomical Union, which traditionally approves celestial names, still has to weigh in on the discoverers' proposal.

"We did not feel rigidly bound by the vote totals, but in the end we decided that Vulcan and Cerberus/Kerberos were pretty good names," said Mark Showalter, a planetary scientist at the SETI Institute who organized the contest. Showalter discussed the selection process in an email to NBC News after Nature reported that the IAU was considering the names.

Shatner, who played Captain James T. Kirk on the original "Star Trek" series, proposed the name Vulcan in honor of the home planet of Kirk's pointy-eared science officer, Mr. Spock. He put out the word to more than a million Twitter followers, and Vulcan ended up receiving 174,062 of the 450,324 votes cast. Cerberus was No. 2 on the list, with 99,434 votes.

Astronomers needed two names — one for the Plutonian moon P4, discovered in 2011; and another for P5, found in 2012. Although Vulcan and Cerberus were the favorites, it was not assured that the discovery team would go with those choices.

Stating the case
Traditionally, Pluto's moons are named after figures of the underworld from Greek or Roman mythology. Cerberus fit that scheme, because that was the name of the dog that guarded the gates of the Greco-Roman underworld. Vulcan, which is the name of the Roman god of fire as well as Mr. Spock's home world, posed more of a challenge.

"For the IAU proposal, I had to make the connection between Vulcan and the Greco-Roman underworld, because I knew that the nomenclature working groups would not be swayed by Star Trek mythology," Showalter explained. "We don't normally associate Vulcan with Pluto, but in fact when you go back to the literature, the Greeks and Romans understood the underworld to encompass everything beneath the surface of the earth, not just the realm of the dead. So Vulcan, the god of lava and volcanoes, really does have a natural connection to underworld.

"That being said, the nomenclature working group has to grapple with the issue that in astronomy, the name Vulcan has previously been associated with a hypothetical object or objects orbiting interior to Mercury. They also will probably have concerns about the fact that Cerberus has already been used as the name of an asteroid. I still believe that it is very important to give the working group latitude in this decision. I remain optimistic that a consensus will emerge."

One possibility would be to use Kerberos as an alternate spelling for Cerberus, to avoid any potential confusion. That's how the discoverers of another moon of Pluto, Nix, got around the fact that there was already an asteroid named after Nyx, the Greek goddess of the night.

Nicknaming an exoplanet
Meanwhile, another celestial naming contest has come to a surprise ending. For weeks, a commercial venture called Uwingu has been running a contest to come up with an unofficial nickname for Alpha Centauri Bb, the closest exoplanet. Thanks to a last-minute surge of vote-buying, the winner of the planet-naming game is "Albertus Alauda."

"I chose this name to honor my grandfather," Jason Lark wrote in his online citation for the name. He explained that Albertus Alauda is the Latin translation of Albert Lark, his grandfather's name.

Uwingu charges $4.99 for each planet nomination, and 99 cents for each vote. A spokeswoman for Uwingu, Ellen Butler, told NBC News in an email Tuesday that Lark "came in with a $742.50 payment last night to take the win." The mass voting is perfectly in accordance with the rules of Uwingu's game.

"I am overjoyed that my nomination won," Lark told NBC News in an email. "I think my grandfather would be very happy, and I hope my citation does him justice. I am very proud of my granddad. As with any other star or planet, they along with their names live on much longer than any one man, and most have a story behind them, such as in the days of old when stars were used to navigate the globe. I would like to think that Albertus Alauda will take its place alongside them in the generations to come, along with the story behind it."

Uwingu was created last year to offer space-based entertainment, to generate revenue and raise money for space science and education projects. The aim is to distribute at least half of the proceeds in the form of grants to programs such as the SETI Institute's Allen Telescope Array, Astronomers Without Borders and the Galileo Teacher Training Program. The contest to nickname Alpha Centauri Bb, which was discovered last year just 4.3 light-years from Earth, brought in about $10,000.

Among the runner-up names were Sagan and Einstein, Ron Paul and Heinlein, Rakhat (the Alpha Centauri planet featured in a sci-fi novel called "The Sparrow"), Tiber (the Alpha Centauri planet that moonwalker Buzz Aldrin made famous in his novel "Encounter With Tiber") and Amara (the first name of the nominator's fiancee). In all, more than 1,200 names were nominated.

Neither Albertus Alauda nor any of those other names has official status with the IAU. In a stinging news release, the IAU said Uwingu's campaigns "will not lead to an officially recognized exoplanet name, despite the price paid or the number of votes accrued."

There is currently no IAU-sanctioned process for approving popular names for the hundreds of extrasolar planets detected beyond our solar system. Instead, astronomers take the name of the star (for example, Alpha Centauri B or Kepler-62) and tack on a letter of the alphabet, starting with "b." (Hence, Alpha Centauri Bb or Kepler-62f.) For the time being, the IAU is sticking with that system, although it said members would discuss establishing a friendlier naming scheme this year.

Meanwhile, Uwingu's "baby book of names" for exoplanets remains open for business. "Also, next week we'll debut a new way to engage in exoplanet naming," Uwingu's CEO, planetary scientist Alan Stern, said in an email.

More about exoplanet names:

• Who gets to name alien planets?
• Newfound planets need better names
• Why Pluto can't have a Mickey moon

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

J.-Y. Li (PSI) / NASA / ESA

Comet C/2012 S1 (ISON) takes on a fuzzy glow in an April 10 image from the Hubble Space Telescope. The blue tint has been added to the black-and-white imagery.

Comet ISON, the long-traveling iceball that skywatchers hope will turn into the "Comet of the Century," takes on a fuzzy glow in an image captured two weeks ago by the Hubble Space Telescope and unveiled on Tuesday.

The picture was taken on April 10, using Hubble's Wide Field Camera 3, when the comet was 386 million miles (621 million kilometers) from the sun and 394 million miles (634 million kilometers) from Earth. That's just inside the orbit of Jupiter. Right now, the comet's brightness is roughly magnitude-16, which means it can only be seen with telescopes. But comet-watchers are hoping that ISON will get dramatically brighter as it swings around the sun in late November. Some have said the comet could match the brightness of Venus or even the full moon.

The reason for those hopes — and the reason for all the "coulds" and "mights" — is that ISON appears to be a long-period comet, coming in from the far reaches of the solar system for the first time in living memory. Such comets are unpredictable: Will they shed lots of dust and glowing gas, or will they turn out to be duds? ISON's orbit is due to bring it within 700,000 miles (1.2 million kilometers) of the sun's surface. That could cause ISON to crumble like Comet Elenin did in 2011, or it could spark a flare-up of Comet Lovejoy proportions.

Unlike Comet Lovejoy, which lit up the Southern Hemisphere's skies during 2011's holiday season, Comet ISON should be visible from the Northern Hemisphere — which means Americans might get an eyeful during this year's winter holidays. (There's that pesky "might"!)

The picture from Hubble helps astronomers get a better fix on the current state of Comet ISON: The nucleus appears to be no larger than three or four miles (five to seven kilometers) across. In Tuesday's image release, the Hubble team says that's "remarkably small, considering the high level of activity observed in the comet so far." The comet's fuzzy head, known as the coma, measures about 3,100 miles (5,000 kilometers) across, or a little less than the distance from New York to Dublin. ISON's tail extends more than 57,000 miles, far beyond Hubble's field of view.

Detailed readings from Hubble could unlock the secrets of ISON's origins, University of Maryland astronomer Michael A'Hearn said in a news release. "We want to look for the ratio of the three dominant ices, water, frozen carbon monoxide, and frozen carbon dioxide, or dry ice," A'Hearn said. "That can tell us the temperature at which the comet formed, and with that temperature, we can then say where in the solar system it formed."  

Comet ISON was discovered last September and is formally known as C/2012 S1 (ISON). It takes its name from the International Scientific Optical Network, a group of observatories in 10 countries managed by Russia's Keldysh Institute of Applied Mathematics.

J.-Y. Li (PSI) / NASA / ESA

This contrast-enhanced image was produced from Hubble's view of Comet ISON to reveal the subtle structure in the inner coma of the comet. Such enhancements help astronomers determine the comet's shape and evolution, plus the spin of its solid nucleus.

More about comets:

• Moon and Comet PanSTARRS pair up
• Flash interactive: Inside a comet
• Cosmic Log archive on comets

The image was created from Hubble data from proposal 13198: J.-Y. Li (Planetary Science Institute), P. Lamy (Laboratoire d'Astrophysique de Marseille), H. Weaver (JHU/APL), M. A'Hearn and M. Kelley (University of Maryland), M. Knight (Lowell Observatory), T. Farnham (University of Maryland), and I. Toth (Hungarian Academy of Sciences).

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

A diminutive robot helped researchers make a substantial discovery during preliminary tests conducted in a tunnel running under the Temple of Quetzalcoatl at the archaeological site of Teotihuacan, the team said Monday.

The team expected to find only one chamber in the last section of the tunnel — but instead, they found three, team leader Sergio Gomez said in a report published by the Mexican newspaper El Universal. The chambers are thought to have been used by Teotihuacan's rulers roughly 2,000 years ago for royal ceremonies or burials, but they're so choked with mud and rubble that they haven't been explored in modern times.

Henry Romero / Reuters

A worker from the National Institute of Anthropology and History walks next to a robot used to explore ruins at the entrance of a tunnel in the archaeological area of the Quetzalcoatl Temple, near the Pyramid of the Sun at the Teotihuacan archaeological site.

That's where the 3-foot-long (1-meter-long) robot known as Tlaloc II-TC comes in: The robot is designed to drive through the tight spaces leading to the back of the tunnel beneath the Temple of Quetzalcoatl, also known as the Temple of the Feathered Serpent. It's equipped with a video camera as well as mechanical arms to clear obstacles.

The current project follows up on an earlier round of robotic exploration by Tlaloc II-TC's predecessor, Tlaloc I, in 2010. (Tlaloc was the Aztec god of rain.)

In 2010, Gomez said there was a "high possibility that in this place, in the central chamber, we can find the remains of those who ruled Teotihuacan." The city was once an influential center of Mesoamerican culture, but little is known about its rulers. Archaeologists have not yet found any depictions of a ruler, or any tomb of a monarch.

El Universal quoted Gomez as saying that the configuration of the space beneath the temple appears to be similar to that of the tunnel running beneath Teotihuacan's Pyramid of the Sun, where four chambers were explored in the 1970s. About 76 meters (250 feet) of the Quetzalcoatl tunnel have already been uncovered, leaving 30 meters (100 feet) or so in the last section. After a round of robotic reconnaissance, archaeologists intend to clear out that section for exploration.

Henry Romero / Reuters

Visitors look on at the archaeological area of the Temple of Quetzalcoatl, near the Pyramid of the Sun at the Teotihuacan archaeological site, about 60 kilometesr (37 miles) north of Mexico City.

Henry Romero / Reuters

Archaeologist Sergio Gomez from the National Institute of Anthropology and History speaks to the media during a news conference in the archaeological area of the Temple of Quetzalcoatl on Monday. A remote-controlled robot has relayed back video images of what appears to be three ancient chambers beneath the temple.

More about Mexican archaeology:

• Google maps ancient Mexican ruins
• Ancient Mexico's dead were given makeovers
• All about Teotihuacan on NBCNews.com

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

A suspected meteor flash wowed observers in Argentina early Sunday — and sparked memories of February's more serious blast over Russia.

The fireball lit up the night in north and central Argentina at about 3:30 a.m. local time, according to accounts from Argentine news outlets. "The sky lit up completely for a couple of seconds and interrupted the calm in this area of Argentina," BarrioOeste.com reported. Witnesses in Catamarca, Tucuman and Santiago del Estero reported sightings.

Twitter users were buzzing over the fireball: A widely shared amateur video showed the green streak and flash in the background of a concert setting. Britain's ITV network reported that the footage was captured in Salta as the folk music band Los Tekis performed at an outdoor venue.

Jorge Coghlan, director of the Astronomical Observatory of Santa Fe, told La Gaceta in Tucuman that the object could have been a space rock about 20 centimeters (8 inches) in diameter that entered the atmosphere at high speed. "This object disintegrated at an altitude high enough to be seen for hundreds of miles," Coghlan said.

Other experts estimated the diameter at 40 to 45 centimeters (15 to 18 inches).

In comparison, the asteroid that came apart over Russia on Feb. 15 was thought to be 17 meters (55 feet) in diameter. That meteor blast created a shock wave that blew out windows and injured more than 1,000 people. No injuries were reported in the wake of the Argentine fireball.

More about meteors:

• East Coast meteor sets off media scramble
• Lyrid meteors bloom in the night sky
• Cosmic Log archive on meteors

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.