Update for 6 p.m ET: One year after their arrival at the moon, NASA's twin Grail spacecraft got a grand sendoff into oblivion, climaxing with a well-orchestrated crash onto a crater's rim. The place where they crashed will be named after Sally Ride, America's first woman in space, who passed away this summer.

Ride was in charge of the Grail mission's MoonKam project, which let students from around the world select targets for the probes' cameras. MIT's Maria Zuber, the mission's principal investigator, announced just after today's double whammy that her team received clearance from NASA to name the crash site after Ride.

"Sally was all about getting the job done, whether it be in exploring space, inspiring the next generation, or helping make the Grail mission the resounding success it is today," Zuber said in a NASA news release. "As we complete our lunar mission, we are proud we can honor Sally Ride's contributions by naming this corner of the moon after her."

The late astronaut's sister, Bear Ride, said the name is a fitting tribute to the space pioneer and her students. "It's really cool to know that when you look up now at the moon, there's this little corner of the moon that's named after Sally, and we hope that kids will really be inspired by that as well," she said during NASA's webcast of the Grail endgame.

The webcast showed mission team members applauding, shaking each other's hands and trading congratulations to mark the end of spacecraft operations at NASA's Jet Propulsion Laboratory. But the main event — the actual crash into the rim of a crater in the moon's north polar region — went unseen. Each of the probes was the size of a washing machine, which means that even though they were going 3,760 mph (1.7 kilometers per second), they didn't make a fiery impact. What's more, at the time of the crash, 5:28 p.m. ET, the impact site was in shadow.

Eventually, NASA's Lunar Reconnaissance Orbiter will take stock of the crash site, NASA spokesman D.C. Agle said. Mission managers don't expect to see any wreckage — just a couple of fresh holes in the ground. However, there's a chance that the blast may have kicked up some water ice or something similarly interesting that the orbiter could detect.

NASA / MIT

An artist's conception shows the Grail probes, known as Ebb and Flow, flying in formation over the moon.

Mission accomplished
The Grail mission's spacecraft entered lunar orbit on Jan. 1 and successfully completed their $496 million mission to map the moon's gravitational field in unprecedented detail. ("Grail" is an acronym standing for Gravity Recovery and Interior Laboratory.)

Earlier this month, the scientists behind the mission reported evidence that the moon was significantly more battered than they thought, early in its history. The fracturing goes deep into the crust and perhaps down further, into the mantle. Researchers also determined that the moon's crust goes 25 miles (40 kilometers) deep, which is not nearly as deep as previously thought.

Such findings are expected to shed light on the process that influenced the formation of the moon as well as Earth, billions of years ago. Before the mission, some scientists suspected that two moons smashed together to form the modern-day moon, in an ancient event nicknamed the "Big Splat." Grail's findings provided no evidence to back up that hypothesis, however.

The Grail mission also made a huge contribution to education and public outreach: The two probes were named Ebb and Flow by elementary-school students from Bozeman, Mont., who participated in a nationwide contest. Both Ebb and Flow were equipped with cameras that could be pointed at targets selected by students from around the world as part of Ride's project.

Although the spacecraft are gone, the job of analyzing the images and data produced by the mission is far from complete.

"Ebb and Flow have removed a veil from the moon, and removing this veil will enable discoveries about the way the moon formed and evolved for many years to come," Zuber said.

Avoiding Apollo sites
NASA opted for a controlled crash primarily to make sure that the Grail didn't end up hitting a historic site on the moon, such as the landing zones for the Apollo lunar modules or unmanned U.S. or Soviet probes. 

The rocket burns that set the stage for the crash were successfully executed on Friday. Grail project manager David Lehman said that before the burns, mission navigators calculated a seven-out-of-a-million chance that one of the probes would hit a historic site. "Now, after these two successful rocket firings, there is zero chance," he said in a status report at the time.

Ebb was the first of the two spacecraft to go down. "Impact in 3, 2, 1, zero," a member of the systems team declared. Flow's crash followed about 25 seconds later. Mission navigators estimated that the two crash sites were separated by 2 miles (3 kilometers).

During their final hours of existence, the two probes were used for one last experiment. Mission engineers had the spacecraft fire their engines until all their remaining fuel was gone, to compare the computer models for fuel consumption against the actual figures.

"Fuel gauges in space are rather challenging, because fuel doesn't sit on the bottom like it does in car tanks on Earth," Agle explained. Grail's last experiment should help engineers get a better handle on the fuel requirements for future missions to the moon, Mars and other cosmic destinations.

Grail project manager Dave Lehman told NBC News that "we have all the data in" from the fuel-tank experiment, and that his team would analyze the data over the weeks ahead. Like many others on the Grail team, Lehman voiced mixed emotions about the end of a mission that went so well from start to finish.

"It's sad," he said, "but things turned out much better than expected."

More about Grail and the moon:

• Kids get their very own 'Earthrise'
• Watch the moon evolve in 3 minutes
• How Ebb and Flow got their names
• Grail snags first video of moon's far side

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.

Gene Cernan / NASA file

Apollo 17 astronaut Harrison Schmitt faces the American flag on the lunar surface with Earth in the black sky above, during a moonwalk on Dec. 12, 1972.

In the 40 years since NASA's last lunar landing, the moon has had its ups and downs as the target for humanity's next giant leap — but the idea of returning to the moon is on the rise again.

Even though President Barack Obama dissed the moon a couple of years ago as a "been there, done that" destination, there's an enduring appeal to our closest celestial neighbor. Part of the appeal comes from planetary science, part of it comes from the moon's potential as a close-in gateway to the solar system — but a big part of it has to do with the moon's hold on our imagination, which took root before the pyramids were built.

When Apollo 17 touched down on Dec. 11, 1972, marking the final lunar landing of the Apollo program, the moon was the agreed-upon finish line for the Cold War's space race. But now the world has changed, and the case for going to the moon is more complicated.

"I've been referring to the moon as the Rodney Dangerfield of the solar system," said Andrew Chaikin, author of "Man on the Moon," the definitive history of the Apollo space program.

The moon hasn't gotten much respect in the past couple of years: After Obama's comment, the White House effectively canceled NASA's Constellation back-to-the-moon program. Instead, NASA set its sights on a visit to a near-Earth asteroid by 2025, and manned trips to Mars in the 2030s. Today, however, there are signs that the idea of going back to the moon isn't that loony after all:

• Two dozen teams are bearing down to try winning the multimillion-dollar Google Lunar X Prize, which goes to the first private venture to send a rover to the moon for a trek to be broadcast on live TV. Two of the teams, Odyssey Moon and SpaceIL, joined forces last month in hopes of taking the grand prize by the end of 2015.
• Last week, the Golden Spike Company proposed sending two-person expeditions to the moon on a commercial basis for $1.4 billion each — which is more than $100 billion less than what NASA was proposing back in 2005.
• China and Russia say they want to put their astronauts on the moon sometime after 2020, with or without NASA. As an initial step toward that giant leap, China is planning to send a robotic lander to the lunar surface next year. India also aspires to send spacefliers to the moon someday.
• NASA has floated the idea of setting up a new space station at a gravitational balance point beyond the far side of the moon, known as Earth-moon L2. The concept is currently stuck in political limbo, however.

Lunar comeback?
A report from the National Research Council faulted NASA last week for lacking a solid strategy for space exploration beyond Earth orbit, and said specifically that NASA's plan to visit an asteroid hasn't gotten enough support from international partners, or the American public, or even within the space agency itself.

John Logsdon, former director of George Washington University's Space Policy Institute, says Obama's next presidential term could provide the opening for a lunar comeback.

"It's certainly in the air here, that changes in the planning for exploration are coming," he said. "There's enough negative pressure that this asteroid goal isn't working, and enough positive pressure to work with the international community that wants to go back to the moon, that the White House will at some point approve the beginnings of a shift in exploration strategy — in which the moon, or at least the space between the earth and the vicinity of the moon, gets a much higher profile."

One of the early test missions for NASA's next-generation heavy-lift rocket — the Space Launch System, or SLS — would involve sending an unmanned Orion capsule all the way around the moon and back in the 2017 time frame. The first crewed mission, set for 2021, would put up to four astronauts into lunar orbit. "It could just as well be an initial mission to this Earth-moon L2 location," Logsdon said.

In September, NASA Deputy Administrator Lori Garver declared that lunar missions would be part of the agency's grand scheme. "We're going back to the moon, attempting a first-ever mission to send humans to an asteroid and actively developing a plan to take Americans to Mars," she said.

Why go?
Chaikin, who has taken on the back-to-the-moon concept as his next crusade, said lunar missions could serve three purposes.

The first aim would be to study the preserved history of the solar system — following up on a scientific story that the Apollo missions were just beginning to uncover.  "I really think the moon deserves to be called a Rosetta stone, because it has unlocked our understanding of how we interpret the clues that we see on other worlds," Chaikin said.

Just as importantly, the moon serves as an "Outward Bound" school for farther space exploration. If a mission goes wrong, NASA could bring the astronauts back in a matter of days — rather than the weeks that an asteroid mission would involve, or the months required for a trip from Mars.

And then there's a phenomenon called the Overview Effect, which could conceivably attract lunar tourists a generation or two from now. "The moon is the only place in the solar system where you can stand on another world and have a consciousness-raising view of Earth," like the view that the Apollo 17 astronauts marveled at 40 years ago, Chaikin explained.

But Chaikin also warns against getting bogged down on the moon. That was the problem with the Constellation program. It called for a permanent settlement to be established on the moon in the 2020s. The cost? You don't want to know. Chaikin said it's better to use the moon "to learn about living off-planet" — to learn how to make use of the moon's water, dirt and rocks, for instance — and then move on to Mars.

The way Chaikin sees it, Apollo 17 was a beautiful ending to one era. Now it's time for the next one.

"Apollo 17 ended the program on a spectacular note," he said. "You can interpret that one of two ways. You can say, wonderful, they found a great way to end it. To some people at NASA, it was just the right time to get out. But on the other hand, here it is, 40 years later, and we're still waiting for someone to pick up where Apollo 17 left off. If we can do that, with the same level of scientific exploration, we'll be in great shape." 

Slideshow: Apollo 17: The last moonshot

NASA

Click through historic photos from humanity's last trip to the moon, the Apollo 17 mission in 1972.

Launch slideshow

More about the Apollo anniversary:

• Apollo 17's Blue Marble leaves its mark on our memory
• Harrison Schmitt remembers Apollo 17 like it was yesterday
• Flashback to 1997: Last moonwalkers look ahead
• Flash timeline: Glory Days on the Final Frontier
• Panoramas.dk: 360-degree view from Apollo 17
• Audio slideshow: Voyage of the Millennium

In addition to marking the 40th anniversary of Apollo 17's lunar landing, the picture of astronaut Harrison Schmitt with the American flag beside him and a tiny Earth above him serves as today's offering for the Cosmic Log Space Advent Calendar, which features views of Earth from outer space on a daily basis from now until Christmas. Check out these other holiday goodies:

More space calendar entries:

• 2012 Cosmic Log Space Advent Calendar
• Day 1: A fantastic Chinese fan
• Day 2: Satellite shows a Grander Canyon
• Day 3: Typhoon stirs awe — and alarm
• Day 4: Glittering nighttime view of Riyadh
• Day 5: Night lights shine on 'Black Marble'
• Day 6: Holy sites seen at night
• Day 7: Blue Marble still leaves its mark
• Day 8: Satellites look into a volcano's hell
• Day 9: Jack Frost nipping at Alaska's nose
• Day 10: Cosmonaut looks down on peaks
• 2011 Cosmic Log Space Advent Calendar
• 2010 Cosmic Log Space Advent Calendar

NASA / AFP

This image from Dec. 7, 1972, shows a view of Earth as seen by the Apollo 17 crew - Gene Cernan, Ronald Evans and Harrison Schmitt - as they traveled toward the moon. The view extends from the Mediterranean Sea area to Antarctica. This was the first time the Apollo trajectory made it possible to photograph the south polar ice cap.

It's been exactly 40 years since NASA sent astronauts to the moon for the last time, and even though more than half of all Americans weren't alive when Apollo 17 got off the ground, the mission still has a big impact on our collective memory. And perhaps the biggest impact comes in the form of a single photograph, the original Blue Marble picture of Earth's full disk.

Hours after their launch on Dec. 7, 1972, Apollo 17 commander Gene Cernan and his crewmates — Harrison Schmitt and Ronald Evans — oohed and ahhed over their home planet, suspended in the blackness outside their window. "I know we're not the first to discover this, but we'd like to confirm ... that the world is round," Cernan told Mission Control.

Astronauts had been seeing the full planet from beyond Earth orbit since 1968, when Apollo 8 made a looping trip around the moon and back. In fact, Apollo 8's "Earthrise" picture of our planet at the moon's horizon also ranks among the most memorable space pictures ever taken. But there was something extraordinary about the view during Apollo 17's trip: The planet's entire disk was sunlit — a sight that astronauts had never captured on film before. The trajectory provided the best look yet at Antarctica, and Schmitt marveled over the clear view of Africa.

"If there ever was a fragile-appearing piece of blue in space, it's the Earth right now," Schmitt said.

When the original picture was released, it made front pages around the world — and it inspired a continuing series of Blue Marble images, including a version that's been commonly used on iPhone displays. Just this week, NASA released a set of "Black Marble" nighttime satellite pictures to add to the Marble repertoire.

Slideshow: Apollo 17: The last moonshot

NASA

Click through historic photos from humanity's last trip to the moon, the Apollo 17 mission in 1972.

Launch slideshow

The Blue Marble wasn't Apollo 17's only cultural legacy. Here are a few other memes that came out of the 12-day mission:

• Doing science in space: Apollo 17 was the first NASA mission to include a professional scientist: Harrison Schmitt, who had a Ph.D. in geology. John Logsdon, former director of George Washington University's Space Policy Institute, recalls that Apollo 16 and 17 were almost canceled during the Nixon administration due to budgetary concerns. "It was the outcry from the science community ... and the fact that Nixon really didn't want to cancel them, that saved those missions," Logsdon said. Apollo 17 was arguably the most scientifically oriented mission to the moon — and helped set the precedent for research on the space shuttle and the International Space Station.
• The beauty of a night launch: The post-midnight launch marked the first time that a NASA manned spacecraft took off at night, and the brilliant blaze of the Saturn 5 rising into the darkness became another iconic picture. It would be more than a decade before the next night launch from Florida: the shuttle Challenger's liftoff on STS-8 in 1983.
• Orange soil: One of the most remarkable scientific discoveries came when Schmitt spotted orange-colored soil during the second of the mission's three moonwalks in the Taurus-Littrow valley. "It's all over! Orange!" he said. He and Cernan made sure that the stuff was included in the mission's 243 pounds (110 kilograms) of lunar rock and dirt — the largest haul of samples ever brought back from the moon. Researchers determined that the orange soil consisted of glass beads formed from lava ejected during volcanic eruptions on the moon, about 3.7 billion years ago. Such findings have helped scientists understand the violent processes that were at work on the moon early in its existence.
• Singin' on the moon: The astronauts had serious work to do during their three days on the lunar surface, but there were moments of levity as well. The best-known moment came when Cernan and Schmitt crooned a tune as they skipped on the moon. "I was strolling on the moon one day, in the very merry month of December," they sang.
• Last man on the moon: When Cernan prepared to climb up the ladder from the moon's surface into the Challenger lunar module for the last time, he told Mission Control that he believed the next steps on the moon would be made "not too long into the future." Logsdon said it was well-known at the time that the next moon mission wouldn't happen for a decade or more. "But I don't think any of us thought it would be 40 years, or really more than a half-century," Logsdon said.

NBC News' Cape Canaveral correspondent, Jay Barbree, told me that Cernan isn't fond of his "last man on the moon" title. "He likes to be called 'the most recent astronaut on the moon,'" Barbree said. "That's his way of saying we're going back."

This week, Bloomberg.com's James Clash quoted Cernan as saying that he "honestly believed it wasn't the end, but the beginning." At the time, he told himself, "We're not only going back, but by the end of the century, humans will be well on their way to Mars."

Cernan also told Clash that he regretted missing out on what would have been another picture for the ages:

"I left my Hasselblad camera there with the lens pointing up at the zenith, the idea being someday someone would come back and find out how much deterioration solar cosmic radiation had on the glass.

"So, going up the ladder, I never took a photo of my last footstep. How dumb! Wouldn’t it have been better to take the camera with me, get the shot, take the film pack off and then (for weight restrictions) throw the camera away?"

How long will it be before someone comes across Cernan's camera and does the damage assessment? If you remember the Apollo moon missions, what did they mean to you back then, and what do they mean to you today? If you don't remember Apollo, do those missions still tug at your psyche, or does this all seem like ancient history? Feel free to leave your remarks or reminiscences as comments below, or send them as emails to cosmiclog@msnbc.com. I'll compile the best of the bunch for a follow-up item next week. We'll also have a look at how the moon may (or may not) figure in future space exploration.

Update for 6 p.m. ET: So who took the Blue Marble picture? That's been the subject of debate for decades, and no one at NASA has ever come up with a definitive answer. "I've actually been to events where all three of them kind of jokingly take credit for it," NASA's Mike Gentry told the Australian Broadcasting Corp. in 1999. The question has apparently been a sore point for Schmitt and Cernan in recent years, but when Barbree asked Cernan about the matter, the mission commander took the standard diplomatic line. Here's what Barbree says Cernan told him about who had the camera: "We were passing it around, and passing it around, and we really don't know who shot it. One of us did."

More about moonshots:

• Harrison Schmitt remembers Apollo 17 like it was yesterday
• Flashback to 1997: Last moonwalkers look ahead
• Flash timeline: Glory Days on the Final Frontier
• Panoramas.dk: 360-degree view from Apollo 17
• Audio slideshow: Voyage of the Millennium
• Apollo 18 in fiction and fact

In addition to marking the 40th anniversary of Apollo 17's launch, the original Blue Marble serves as today's offering for the Cosmic Log Space Advent Calendar, which features views of Earth from outer space on a daily basis from now until Christmas. Check out these other holiday goodies:

More space calendar entries:

• 2012 Cosmic Log Space Advent Calendar
• Day 1: A fantastic Chinese fan
• Day 2: Satellite shows a Grander Canyon
• Day 3: Typhoon stirs awe — and alarm
• Day 4: Glittering nighttime view of Riyadh
• Day 5: Night lights shine on 'Black Marble'
• Day 6: Holy sites seen at night
• 2011 Cosmic Log Space Advent Calendar
• 2010 Cosmic Log Space Advent Calendar
• The Atlantic: Hubble Advent Calendar
• Zooniverse Advent Calendar

A group of space veterans and big-name backers today took the wraps off the Golden Spike Company, a commercial space venture that aims to send paying passengers to the moon and back at an estimated price of $1.4 billion or more for two.

The venture would rely on private funding, and it's not clear when the first lunar flight would be launched — but the concept received a vote of support from NASA, which canceled its own back-to-the-moon plan two and a half years ago.

Golden Spike's announcement came on the eve of the 40th anniversary of the launch of Apollo 17, the last manned moonshot. Backers of the plan, including former NASA executive Alan Stern and former Apollo flight director Gerry Griffin, discussed the company's strategy at a National Press Club briefing in Washington.

"The time is ripe for commercial human lunar exploration," Griffin told journalists.

Stern said Golden Spike's experienced team of board members and advisers gave him confidence that they'd be able to make good on what sounds like a supremely overambitious plan. "We realize this is the stuff of science fiction," he said. "We intend to make it science fact." 

Stern, a planetary scientist who was NASA's associate administrator for science in 2007-2008, is Golden Spike's president and CEO, while Griffin is chairman of the board. Other board members include new-space entrepreneur Esther Dyson and Taber McCallum, co-founder and CEO of Paragon Space Development Corp. The lineup of advisers taps into a who's who of space figures, including former House Speaker Newt Gingrich, former NASA shuttle program manager Wayne Hale, former NASA engineer Homer Hickam and Bill Richardson, who has served as U.N. ambassador, energy secretary and the governor of New Mexico.

The venture also numbers United Launch Alliance, Armadillo Aerospace, Masten Space Systems and several other space-industry players on its team for the lunar lander system.

Golden Spike takes its name from the ceremonial spike that joined the rails of the first transcontinental railroad across the United States in 1869, a milestone that opened up the Western frontier to new opportunities.

"We’re not just about America going back to the moon; we’re about American industry and American entrepreneurial spirit leading the rest of the world to an exciting era of human lunar exploration," Stern said in the venture's first news release. "It’s the 21st century, we’re here to help countries, companies, and individuals extend their reach in space, and we think we’ll see an enthusiastic customer manifest developing.”

Ambitions and doubts
Golden Spike's news release said the venture would make use of existing rockets as well as commercial spacecraft that are currently under development to send expeditions to the lunar surface, with the estimated cost of a two-person lunar surface mission starting at $1.4 billion. That's roughly equivalent to the cost of a flagship robotic mission to the moon or Mars, such as the Curiosity-class rover mission that NASA is planning to launch to the Red Planet in 2020.

Stern said Golden Spike's mission architecture has been in development for two years. Each expedition would involve two sets of two launches each: The first set would put the pieces in place to pre-position a lander in lunar orbit. The second set would deliver a two-person crew to hook up with the lander, head down to the lunar surface, return to lunar orbit and then sail home.

That architecture could be put in place for $7 billion to $8 billion, Stern said. "This is a breakthrough cost," he said. In addition to the $1.4 billion for each two-person expedition, Golden Spike would derive revenue from media ventures associated with each moonshot, Stern said.

Golden Spike said market studies indicated that 15 to 20 expeditions could be undertaken in the decade after the first landing. However, no time frame was given for that landing. That's just one of the gaps in Golden Spike's plan. Among the other questions yet to be resolved:

• How will Golden Spike fund its operations during the buildup to the first flight? Stern said the venture needed several hundred million dollars to proceed with mission development. Unlike the Planetary Resources asteroid-mining venture, Golden Spike has no billionaire backers. Instead, Stern said his venture would rely on making enough advance sales to attract financing, as the Boeing Co. would for a new airplane. He acknowledged that when it came to being able to land on the moon by 2020, the "long pole in the tent" would be the ability to make those sales.  
• Can private-sector efforts produce a workable lunar launch and landing system at a cost far less than the $100 billion that NASA said it would cost in 2005? Stern said recent advances in technology would lower the cost of spacecraft development, but he acknowledged that "re-creating Apollo capability, even 40 years later, is hard." As detailed on the venture's Web site, the mission architecture relies on launch vehicles currently in use or under development, such as ULA's Atlas 5 or SpaceX's Falcon 9 and Falcon Heavy. SpaceX's Dragon capsule is under consideration as the crew vehicle. The lunar lander, however, has yet to be developed. Stern said Golden Spike is working with its partners to study concepts for the lander. 
• Are Golden Spike's assumptions about the demand for lunar missions correct, even if the price point is in its estimated range of $1.4 billion and up? Stern said Golden Spike was in contact with one individual who might be able to pull together a moonshot deal, but the prime market for missions would be national space agencies. "We've already had conversations with some national space agencies, and they've expressed their interest," he said. Stern declined to name names, but said that the agencies were based in Europe and Asia. 
• What kinds of relationships would Golden Spike be able to forge with NASA and international space efforts? Stern and Griffin did not say that NASA would be involved in Golden Spike's moonshots, but they suggested that the ticket window would be open. "By all means, if NASA wants a ride, we'd be glad to put them on our railroad," Griffin said. Stern said Golden Spike has also retained counsel to help sort out the export-control issues associated with foreign sales. 

Reaction, pro and con
NASA's associate administrator for communications, David Weaver, issued a statement that portrayed the venture in a positive light while steering clear of a formal endorsement.

"This type of private-sector effort is further evidence of the timeliness and wisdom of the Obama administration's overall space policy— to create an environment where commercial space companies can build upon NASA’s past successes, allowing the agency to focus on the new challenges of sending humans to an asteroid and eventually Mars," Weaver said. "As the private sector works to develop human missions to the International Space Station and eventually the moon, NASA will continue to develop new technologies and capabilities to advance the frontier ever further into space."

But John Pike, a longtime expert on space policy who heads GlobalSecurity.org, said he was "deeply skeptical" about Golden Spike's business plan. "If you could do it this cheap, somebody would have already done it," he told me.

Even if a lunar exploration program could be created for $8 billion, Pike said he didn't think the moonshot market would match Stern's expectations. "The implication is that they've got 20 countries that want to shoot people to the moon. I doubt it," he said.

India and China might be interested — but after that, Pike said, "How many countries are going to be prepared to spend money to be the 12th to land on the moon? ... I think a lot of these rocket men are just taking too many happy pills."

Are you optimistic or skeptical about Golden Spike's prospects? Either way, feel free to weigh in with your thoughts in the comment space below.

More about moonshots:

• Private moon race may spark 'water rush'
• Fly me to the moon? That'll be $100 million
• Gingrich promises US moon colony by 2020
• Russian official says Moscow needs a moon base
• Will China take over the 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.

Andrew Wall

Astrophotographer Andrew Wall captured images of the moon before and during the penumbral lunar eclipse (left and right, respectively). "The images were taken from my backyard in Paralowie, South Australia," he said in an email. Six frames were stacked to produce each image.

Did you catch today's eclipse? You probably didn't notice the penumbral lunar eclipse unless you knew it was coming — but fortunately, skywatchers around the world were clearly ready.

This photo by Australian astrophotographer Andrew Wall illustrates just how subtle the eclipse was. Earth's fuzzy shadow dimmed the bright lunar disk at the height of the eclipse, which translated to 9:33 a.m. ET today.

The dimming effect was muted because the moon traveled just through the very edge of the shadow this time around — and not through the deepest part of the shadow, as it did during last December's total lunar eclipse.

The prime viewing area included Australia and the Pacific as well as Alaska and most of Asia.

"There was a very subtle darkening of the lunar limb at totality; barely noticeable to the untrained eye," Pakistani skywatcher Ramiz Qureshi told SpaceWeather.com in a report from Karachi. "In fact, I nearly missed it until a friend reminded me."

Qureshi put together a close-up shot and a wider-angle photograph to create this composite view of the eclipse. We also received a picture from Terry Staats in Chiba City, Japan, via NBC News' FirstPerson photo-uploading page. If you missed today's subtle show, there'll be three replays next year — including a partial lunar eclipse on April 25 and penumbral eclipses on May 25 and Oct. 18.

For more views of today's lunar eclipse, as well as the total solar eclipse that took place two weeks ago, check out SpaceWeather.com's eclipse photo gallery.

Rob Kaufman

Rob Kaufman, an astrophotographer from Bright, Australia, also captured a pre-eclipse picture of the moon at 12:00 GMT Wednesday (left), and a picture at maximum eclipse at 14:34 GMT (right).

Ramiz Qureshi

A composite photo from Ramiz Qureshi in Karachi, Pakistan, shows the slightly dimmed moon above an industrial skyline.

Romeo Ranoco / Reuters

A penumbral eclipse of the moon is seen over Manila in the Philippines. The term "penumbral" refers to the partially shaded outer region of a shadow that an object casts. This type of eclipse occurs when the moon passes through the faint penumbral portion of Earth's shadow.

Terry Staats

Earth's shadow slightly darkens the moon over Chiba City in Japan.

More about lunar eclipses:

• Flash interactive: What causes a lunar eclipse?
• Why a lunar eclipse won't drive you loony
• Nine cool facts about lunar eclipses
• How super was that Supermoon?

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 via email. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Hong Kong Observatory

Time-lapse photos show the subtle effect of a penumbral lunar eclipse.

It's no Supermoon, but if you look closely at the right time from the right place, you can see Earth's shadow darken the lunar disk early Wednesday — and even if you're not at the right place, you just might be able to catch the subtle celestial show online.

The penumbral lunar eclipse hits its peak at 9:33 a.m. ET (14:33 GMT), which is too late for the U.S. East Coast: By then, the full moon has set and the sun is up. South America, West Africa and Antarctica are also out of the picture. But most of the rest of the world will see at least part of the eclipse, such as it is. The chart below from NASA's eclipse website shows you what can be seen where, and TimeandDate.com helps you figure out the schedule for your own locale.

Fred Espenak / NASA

The white section of this map indicates where this week's penumbral lunar eclipse will be visible in its entirety. Observers watching from the light gray sections will see only part of the eclipse. No part of the eclipse can be seen from the dark gray section of the map.`

If you're in the eclipse zone, don't expect a spectacle like the total solar eclipse that took place earlier this month — or even like this year's other lunar eclipse, which darkened a piece of the Supermoon in June.

On Wednesday, the moon will pass through the lightest part of the shadow cast by our planet — the penumbra, which lets some sunlight shine through. If you could watch the event from the moon's surface, you'd see Earth cause a partial solar eclipse. The result is that the moon's brightness dims somewhat, but it's not enough to be noticeable unless you know what's coming.

What's more, the moon is at the farthest point of its orbit during this eclipse — about 30,000 miles (50,000 kilometers) farther away than June's Supermoon. The result is that the moon is about 30 percent dimmer than the Supermoon was.

The outlook for watching the eclipse online is dim as well. Slooh Space Camera is prepared to stream a telescopic video view of the moon from Hawaii at 9:15 a.m. ET (14:15 GMT), but the weather at the telescope site is not looking good, Slooh President Patrick Paolucci told me this evening.

"At this point, the penumbral event is in serious jeopardy," Paolucci said in an email. "The event will continue to count down on Slooh, but we may have to pull it tonight. ... We only go live when our feeds are live."

Perhaps the coolest thing about this eclipse is that it demonstrates one of the rules of celestial mechanics: Every time there's a total solar eclipse, you can count on having a lunar eclipse of some sort either two weeks earlier or two weeks later. That's because totality occurs when the sun, moon and Earth are precisely aligned during the moon's new phase — and the moon will still be lined up for an eclipse when it's facing Earth's far side for the full phase. The Inconstant Moon website provides further explanation of the eclipse seasons.

Even if the eclipse webcast is a washout, there'll be more cosmic shows to come: Paolucci says Slooh is planning a real-time video feed featuring Jupiter and its Great Red Spot on Sunday, starting at 8:15 p.m. ET (01:15 GMT Dec. 3). That's the night when Jupiter will be at its closest distance to Earth until the summer of 2021. Slooh's telescopic view is due to come from an observatory on the Canary Islands, accompanied by commentary from Paolucci and astronomer Bob Berman.

After that, stay tuned for the Geminid meteor shower, which peaks on the night of Dec. 13-14. This year's Geminids should make for a super show, because the moon will be in its new phase, leaving the skies clear for the sparkle of up to 100 shooting stars per hour. Factor in a series of space station sightings, and you've got more than enough to make up for a less-than-super lunar eclipse.

More about lunar eclipses:

• Flash interactive: What causes a lunar eclipse?
• Tips for photographing the penumbral eclipse
• Why the lunar eclipse won't cause madness
• Nine cool facts about lunar eclipses
• How super was that Supermoon?

Got eclipse? If you capture a super picture of the less-than-super moon, share it with the rest of us via NBC News' FirstPerson website for user-generated content. We'll publish a selection of images in a follow-up posting on Wednesday.

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 / Boeing via NASASpaceflight.com

An artist's conception shows a deep-space transfer vehicle flying near a exploration gateway platform at right.

A concept that calls for building a deep-space outpost beyond the moon's orbit has stirred up some positive buzz from space pioneers — including Apollo 11 moonwalker Buzz Aldrin.

Over the weekend, the Orlando Sentinel reported that top NASA officials have chosen the construction of a space exploration platform at a gravitational balance point known as EML-2, or Earth-moon Lagrange point 2, as the agency's next major mission. The outpost would be held in an orbit 277,000 miles away from Earth, and 38,000 miles beyond the moon.

The concept has been under study for months, and the Sentinel reported that NASA Administrator Charles Bolden briefed the White House on the preferred plan's details this month. There's been no information from NASA or the White House on the time frame for deciding whether to move ahead with the concept.

Right now, NASA has been focusing on development of the Orion deep-space capsule and the heavy-lift Space Launch System, or SLS. NASA sees Orion and SLS as critical elements for the deep-space construction project. The first unmanned test of the Orion-SLS combination is currently set for 2017. A later test flight, now scheduled for 2021, would send astronauts on a path looping around the moon and returning to Earth without stopping. Getting the EML-2 station ready for human habitation would presumably take longer.

For now, NASA and its partners have committed themselves to supporting operations on the International Space Station through at least 2020. President Barack Obama has set a longer-range goal of sending astronauts to a near-Earth asteroid in the mid-2020s, and to Mars and its moons in the mid-2030s.

The outpost at EML-2 has been cast as an "exploration gateway platform" — a potential stopping point on the way to those farther-out destinations, as well as a potential staging area for lunar missions.

David A. Kring / LPI-JSC Center for Lunar Science and Exploration

The Lagrange points for the Earth-moon system are the places where the gravitational pull exerted by the two celestial bodies come close to balancing out. NASA reportedly favors a plan to put an outpost at the Earth-moon L2 point. Astronauts parked there could teleoperate robots on the lunar far side.

Aldrin has long urged NASA to set up a similar "floating launching pad" at a different balance point between Earth and the moon, called EML-1 or L1, and this weekend he said that platforms at L1 or L2, plus fueling depots for spaceships, would serve as appropriate "intermediate steps" for voyages to Mars and other worlds.

"It's part of my unified space vision," he told me during an international gathering of spacefliers and mission managers at Seattle's Museum of Flight.

Aldrin's vision calls for NASA to lead in the construction of the infrastructure needed for space transport beyond Earth orbit, while leaving the development of facilities on the moon's surface to commercial ventures. A human-tended station at EML-1 or EML-2 could help direct the robotic construction of habitats and factories on the moon, to be occupied at a later time by humans.

"Those are steppingstones in confidence and training for interplanetary spacecraft," Aldrin said.

The eventual goal would be to have a human-tended station on the Martian moon Phobos, directing robots to build facilities for permanent residents on the Red Planet. And then? "We make a commitment to permanence," Aldrin explained. "It's like the Pilgrims on the Mayflower."

Is it doable?
Aldrin noted that he and Apollo 11 commander Neil Armstrong made the first moon landing in 1969, which was 66 years after the Wright brothers' first heavier-than-air flight in 1903. He thought it was technologically doable to plan for a Mars landing 66 years after the moon landing, which would be in 2035. But is it politically doable?

"There's one thing that doesn't exist: leadership. ... We need a presidential decision," Aldrin said. His suggestion? Lay the groundwork for exploration beyond Earth orbit, and get ready for a future president to make a JFK-style "We Choose to Go to Mars" announcement on July 20, 2019 — the 50th anniversary of the moon landing.

"Humanity is destined to explore, settle and expand into the universe," Aldrin said during a panel discussion on Sunday, "but doing so urgently requires a rekindling of America's space program."

Other astronauts issued similar calls for step-by-step exploration: Skylab astronaut Owen Garriott, for example, said "there is a lot of work that needs to be within the orbits of the earth and the moon" before astronauts can be sent to near-Earth asteroids or farther-out destinations. Later, he told me that "I agree with Buzz" on the idea of creating outer-space steppingstones to Mars.

Jim Lovell, who went around the moon during the Apollo 8 and Apollo 13 missions, recalled that he and Apollo 11's Armstrong were in training for their spaceflights when President John F. Kennedy was killed in 1963, ending a White House era that came to be known as Camelot.

Armstrong's death last month could be seen as a similar ending of an era, Lovell said. "The passing of Neil Armstrong closed the book on the Camelot of manned spaceflight," he told the Seattle audience. "Now we have to write a new chapter."

Is it affordable?
In this age of tighter budgets, how much will the spaceflight saga's new authors be able to write? The scenario for the beyond-the-moon outpost calls for using spare parts that were built for the International Space Station, as well as hardware provided by Russia and Italy. But even with those money-saving measures, the plan would still call for "modest increases" in NASA's budget — which runs counter to the current expectation that NASA will have to cope with lower funding levels going forward.

There are also technical questions to resolve: For example, how will astronauts cope with the higher radiation levels in deep space? NASA has been studying various schemes for radiation shielding, but none of those concepts is currently ready for prime time.

Then there's the continuing debate over whether the Orion-SLS system will turn out to be affordable in the long run. Current estimates put the cost of development at roughly $18 billion through 2017, and as much as $35 billion by the time the test program is complete. Charles Lurio, an independent space policy consultant who has long been critical of the SLS program, said it would make more sense to build the deep-space outpost using commercial launch vehicles.

"NASA is trying to find uses for a rocket that Congress forced the agency and the White House to accept," he told me. "You can do this mission much more cheaply using rockets such as Falcon Heavy, Falcon 9, Atlas and fuel depots. Mega rockets like the SLS are for showing off, not for serious space exploration.”

What do you think of the idea of building an outpost beyond the moon? How would you balance space ambitions and budget realities? Feel free to weigh in with your comments below.

More about future frontiers:

• Gallery: Seven out-of-this-world destinations
• Romney lays out his policy for space exploration
• NASA considers outpost beyond moon's far side
• Commentary: From the earth to the moon, then beyond

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 file

Neil Armstrong's shadow appears in an image that was taken during the Apollo 11 lunar mission in 1969 for a 360-degree panorama. Click on the image to play with an audio-enhanced panorama from PhotoJPL.com.

The death of first moonwalker Neil Armstrong and the success of NASA's Curiosity rover have reignited interest in the idea of taking a spin on the moon and Mars, at least virtually. It may be a decade or two before astronauts once again walk on the moon, or take the next giant leap to the Red Planet. In the meantime, 360-degree interactive panoramas give you a sense of what those walks will be like. Here's a quick roundup of the coolest 360-degree views:

Walking on the moon
Armstrong, who passed away last weekend at the age of 82, was the first photographer to produce a 360-degree panorama on the surface of another celestial body. The pictures that make up the all-around mosaic show crewmate Buzz Aldrin working near the lunar module, the glare of the sun in the opposite direction, and Armstrong's shadow on the lunar surface.

Every Apollo mission that made it to the surface since then has featured at least one all-around picture. In Armstrong's honor, PhotoJPL.com has produced a zoomable, spinnable 360-degree display of the Apollo 11 scene. But to get the full Apollo lineup — including the must-see batch from Apollo 17, the last lunar mission — you'll want to check out Panoramas.dk or Moonpans.com. 

The Lunar and Planetary Institute offers an atlas of the source images, which were taken with the Hasselblad 70mm camera used on all of the Apollo missions. If you want to find Cat's Paw Hills in Armstrong's panorama, or Hadley Delta in the Apollo 15 panorama made by Jim Irwin, this is the place.

JPL-Caltech / NASA / MSSS / Hans Nyberg

A panoramic picture from Mars shows the shadow of the Curiosity rover in the foreground as well as Mount Sharp on the horizon. Gaps in this picture have been filled out by Hans Nyberg for a pan-and-zoom panorama. Click on the image to give the interactive version a spin.

Roving on Mars
NASA's Spirit and Opportunity rovers have sent back years' worth of 360-degree vistas from the places they've visited, and Curiosity has already added some fantastic views to the panoramic photo album. You'll find more than 30 all-around views at the website for the Pancam imaging system used on Spirit and Opportunity, plus scores of partial panoramas and mosaics. NASA's website for the Mars Exploration Rovers also rounds up lots of panoramic views, including 3-D versions.

Pan-and-zoom versions of the Spirit and Opportunity all-arounds can be found at Marspans.com and Panoramas.dk. The Mars Panoramas website offers the rover all-arounds as well as 360-degree views from the Mars Pathfinder lander (1997) and the Phoenix Mars Lander (2008).

When it comes to Curiosity, Hans Nyberg of Panoramas.dk has done up a great 360-degree view of the rover's landing site in Gale Crater. This version of the picture has been adjusted by NASA so that the lighting reflects earthly conditions rather than the dull red of filtered Martian sunlight. In addition, Nyberg has filled in the parts of the Martian sky that were missing in the data sent back by Curiosity.

Nyberg also has a black-and-white panorama of the Martian terrain as seen on Aug. 22, after the six-wheeled Curiosity made its first move. A similar view can be seen on the PhotoJPL website. Be sure to check out the rover's tracks in the foreground. 

Arounder Mars offers panoramas from Curiosity as well as Spirit, Opportunity and Pathfinder, although its sepia-toned view of Curiosity's surroundings doesn't include the latest pictures of 3-mile-high Mount Sharp (also known as 5-kilometer-high Aeolis Mons). PhotoJPL also has a Sharp-less panorama of the Curiosity landing site.

Over at the 360Cities website, Andrew Bodrov has updated his popular black-and-white Mars Curiosity panorama to include Mount Sharp — and he's added some real stunners, including this full-color, 360-degree view. The Wall Street Journal has an interactive graphic that serves up three 360s: the black-and-white and color views of the landing site, as well as a post-drive panorama in black and white only.

All these pan-and-zoom views are based on the imagery provided by NASA, of course, and there are several places you can go to get the full spread without the clickability. Here are just a few of my favorite haunts. Got more to add? Feel free to pass them along in your comments below.

Correction for 9:30 p.m. Sept. 4: An earlier version of this posting incorrectly stated that Nyberg enhanced the lighting in the color 360-degree panorama. Instead, he selected a rendering of the scene that was enhanced by NASA to look more Earthlike. This webpage from the Jet Propulsion Laboratory's Photojournal demonstrates the difference between the raw version and the enhanced version. Also, for a time, I improperly embedded Nyberg's panorama rather than providing an outward link.

More ways to satisfy your curiosity about Curiosity:

• NASA's Curiosity image gallery
• UnmannedSpaceflight.com: MSL forum
• DB Prods: Curiosity and more from Mars
• Planetary Society: Curiosity
• The Gale Gazette
• Martian Vistas

360-degree panoramic views from NBCNews.com:

• October 2011: Occupy Wall Street in New York's Zuccotti Park
• May 2012: Annular solar eclipse witnessed from Lassen Peak
• July 2012: At home in a retired Boeing 727 jet

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.

Bill Ingalls / NASA

NASA photographer Bill Ingalls, who was in Cincinnati to take pictures during Apollo 11 moonwalker Neil Armstrong's family memorial ceremony on Aug. 31, snapped this picture of the "blue moon" hanging over the Queen City's skyline. See some of Ingalls' pictures from the memorial ceremony.

Tonight's blue moon may not be as rare as it sounds, but it's still special — as is every glorious full moon, whichever color you use to describe it.

Actually, the term "blue moon" is something of a misnomer. There's no reason for the full moon to be any bluer than usual (though it's certainly possible for the moon to take on a blue tinge). Instead, it has to do with the extra occurrence of a full moon in a given calendar cycle.

Various cultures have used different terms to describe that extra lunar cycle — Adhik Maas for Hindus, or an extra month of Adar for the Jewish calendar. The Maine Farmers' Almanac used the term "blue moon" to describe an extra moon in a particular quarter of the year.

Then, in 1946, an amateur astronomer named James Hugh Pruett wrote about the phenomenon for Sky & Telescope magazine, in the context of the old saying that a rare occurrence happened only "once in a blue moon."

Only problem was, he got it wrong.

Pruett described the blue-moon phenomenon as the second full moon in a calendar month. Sky & Telescope stuck with that, and the definition has been used (and hotly debated) ever since. If you go along with the definition, then tonight's full moon is blue due to the fact that it follows a full moon on the night of Aug. 1.

There's another long-debated issue surrounding blue moons: You could argue that they happen way too often to be considered as rare as a "blue moon" in the proverbial sense. The interplay of the lunar and solar calendars dictates that a blue moon should occur, on average, every 2.7 years.

Astrophysicist Neil deGrasse Tyson summed up the issue a couple of days ago in a Twitter update: "A month's second full moon is the blue moon. Not rare. More frequent than presidential elections, yet nobody calls them rare."

Technically speaking, the moon is already a few hours past its full phase — but it's still well worth taking note of, and not just because it's the last blue moon until July 31, 2015. It provides a fitting opportunity to pay tribute to history's first moonwalker, Neil Armstrong, who passed away last weekend. In fact, Armstrong's family is urging you to look at the moon in Neil's honor.

"The next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink," the family said.

Photographers around the world have already been getting great moon shots. Here's a sampling of the "blue moon" views:

Biswaranjan Rout / AP

A boy rides his bicycle over a stretch of sand on the outskirts of the eastern Indian city of Bhubaneswar as the "blue moon" shines above in Aug. 31.

Muhammad Hamed / Reuters

A full moon shines over Amman, the capital of Jordan, on Aug. 31.

Robert Atanasovski / AFP - Getty Images

A full moon is seen behind tree branches in the Macedonian city of Skopje on Aug. 31. According to NASA, this is the second time in August that a full moon has been seen. The first was on the night of Aug. 1-2. This phenomenon is referred to as a "blue moon."

Vesa Vauhkonen

Vesa Vauhkonen created this multiple-exposure photographic view of the moon rising over Rautalampi, Finland, on Aug. 30.

Daisuke Tomiyasu

The clouds over Kobe, Japan, take on a fittingly blue hue in this picture taken by Daisuke Tomiyasu on Aug. 31.

Louisa Gouliamaki / AFP - Getty Images

Greeks and tourists gather at the Roman Agora in Athens, which is open all night as part of a full-moon celebration on Aug. 31. A number of archaeological sites and museums around Greece opened at night, with events and concerts celebrating the second full moon of August, known as a "blue moon."

Louisa Gouliamaki / AFP - Getty Images

A picture taken on Aug. 31 shows the full moon above the ancient Acropolis hill in Athens.

Inge Harsten

Inge Harsten, who lives in Fredrikstad, Norway, used a filter to add an appropriate color to this picture of the "blue moon."

Petros Karadjias / AP

The full moon rises over the sea at Konnos beach near Ayia Napa and Protaras resort in the southeast of the island of Cyprus on Aug. 31.

For still more blue-moon pictures, check out SpaceWeather.com's photo gallery and NASA's Flickr site for blue-moon imagery. If you snap a great picture of the moon tonight, please consider sharing it with us. Use our FirstPerson upload tool to send us your moon shot, and we'll pass along a sampling of the photos we receive.

Where in the Cosmos
Vesa Vauhkonen's moonrise montage served as the subject of this week's "Where in the Cosmos" photo quiz on the Cosmic Log Facebook page. It took a while this time, but John Culp and Brian Svacina eventually guessed that the photo was taken in Finland. To reward their geographical smarts (or was it just plain luck?), I'm sending them pairs of 3-D glasses, provided courtesy of Microsoft Research's WorldWide Telescope project. Those red-blue glasses will add an extra dimension to moon pictures like this one. Got 3-D? Click the "like" button for the Cosmic Log Facebook page and get ready for next Friday's quiz.

Update for 8:20 p.m. ET: The Phrase Finder delves deeply into the origins of the phrase "blue moon," meaning a rare event, and appears to have come up with a sensible explanation. In 16th-century England, the expression was apparently used to describe an impossible event, like pigs flying. The phrase pops up in a sarcastic context in a 1528 work by William Barlow, Bishop of Chichester, titled "Treatyse of the Buryall of the Masse": "Yf they saye the mone is belewe, we must beleve that it is true."

It took centuries longer for the phrase to describe something that hasn't happened in quite a while. The Phrase Finder cites this quote in Pierce Egan's "Real Life in London" (1821): "How's Harry and Ben? — haven't seen you this blue moon." Meanwhile, the Maine Farmers' Almanac put its own astronomical twist on the term, going back to the 19th century.

More moon shots:

• Your views of the supermoon
• Slideshow: Hits from 2012's supermoon
• Darkness falls on the moon in June
• Slideshow: 50 years of moon views

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.

Neil Armstrong / NASA file

One of the most unusual and oft-used pictures showing Neil Armstrong on the moon is this one, which is actually a reflection of a lunar scene on Apollo 11 crewmate Buzz Aldrin's helmet visor. The reflection shows a fuzzy image of Armstrong holding the Hasselblad 70mm camera, with Aldrin's shadow stretching in front of him. Armstrong is flanked by the lunar module and scientific experiments. The cross is a "fiducial" mark used for calibration. For more about the picture, check out an analysis from the Apollo 11 Lunar Surface Journal.

The reasons for first moonwalker Neil Armstrong's reticence on Earth may be psychologically complex, but there's a simpler reason why pictures of him on the moon are so scarce: In addition to being the commander of the history-making Apollo 11 mission in 1969, he was the chief photographer for the mission's moonwalk.

Nearly all of the pictures that were taken during the first moon landing show Armstrong's sole crewmate on the moon, Buzz Aldrin, because Armstrong was stuck behind the camera.

But it'd be an overstatement to claim that there's only one picture showing the recently departed astronaut during his lunar walkabout. All you have to do is notice that different people have pointed to different pictures as the "only one."

Armstrong may have taken most of the scores of photographs that were captured on the lunar surface, but Aldrin also had a couple of turns behind the Hasselblad 70mm camera, and there were other cameras as well: the famous TV camera that transmitted that "one small step," and a 16mm movie camera that was looking out a window from the lunar module. "The Cameras of Apollo" website provides a rundown. 

Take a look at these pictures showing Armstrong during the moonwalk, then take a spin through our slideshow featuring the highlights of Armstrong's life, before, during and after Apollo 11:

NASA / CollectSpace / Andrew Chaikin

Some frames of Neil Armstrong working on the moon were captured on a 16mm movie camera that was set up on the Apollo 11 lunar module to record the action. This high-definition scan of a movie frame provides the clearest view of Armstrong's face while he was on the lunar surface. That's because Armstrong had raised his gold-colored outer visor while he was working. Check out this CollectSpace tale about the picture.

Buzz Aldrin / NASA file

Apollo 11 commander Neil Armstrong works next to the lunar module with his back to the camera, in a picture that was taken by crewmate Buzz Aldrin as part of a panoramic series.

Buzz Aldrin / NASA file

This picture shows Apollo 11's solar wind experiment on the right, and the back of Neil Armstrong's backpack at the left edge of the frame.

Slideshow: Neil Armstrong: 1930 - 2012

See images from the career of astronaut and American hero Neil Armstrong.

Launch slideshow

More scenes of spaceflight:

• Audio slideshow: Voyage of the Millennium
• NBC video: Highlights of spaceflight
• Slideshow: NASA's highs and lows
• Timeline: Glory Days on the Final Frontier
• Space gallery on NBCNews.com

For much more about the photos from Neil Armstrong's spaceflights, check out this roundup from CollectSpace.

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: Neil Armstrong: 1930 - 2012

See images from the career of astronaut and American hero Neil Armstrong.

Launch slideshow

There are just a couple of things that Neil Armstrong's family wants you to do to pay tribute to the first moonwalker's life and legacy: Honor his example, and wink at the moon.

Armstrong, 82, is survived by his wife Carol, two sons by his former wife Janet, a stepson and stepdaughter, 10 grandchildren, a brother and a sister. Here's the full statement issued by the family after his death:

"We are heartbroken to share the news that Neil Armstrong has passed away following complications resulting from cardiovascular procedures.

"Neil was our loving husband, father, grandfather, brother and friend.

"Neil Armstrong was also a reluctant American hero who always believed he was just doing his job. He served his Nation proudly, as a navy fighter pilot, test pilot, and astronaut. He also found success back home in his native Ohio in business and academia, and became a community leader in Cincinnati.

"He remained an advocate of aviation and exploration throughout his life and never lost his boyhood wonder of these pursuits.

"As much as Neil cherished his privacy, he always appreciated the expressions of good will from people around the world and from all walks of life.

"While we mourn the loss of a very good man, we also celebrate his remarkable life and hope that it serves as an example to young people around the world to work hard to make their dreams come true, to be willing to explore and push the limits, and to selflessly serve a cause greater than themselves.

"For those who may ask what they can do to honor Neil, we have a simple request. Honor his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink."

More about Neil Armstrong:

• Neil Armstrong, first man to walk on moon, dies at 82
• President and VIPs pay tribute to Neil Armstrong
• Internet responds to first moonwalker's death
• Debunking nine myths about Neil Armstrong
• Slideshow: A look back at an American hero's life
• Timeline: Glory Days on the Final Frontier
• What we didn't know about the moonwalk
• Neil Armstrong would still choose to go to the moon
• Video: NBC's initial report on Neil Armstrong's death
• Video: NBC's Bruce Hall recaps Neil Armstrong's career
• Video: Friends reflect on Neil Armstrong's passing

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 dwarf planet and the search for new worlds.

NASA / GSFC / ASU

An enhanced close-up of the Apollo 11 landing site from NASA's Lunar Reconnaissance Orbiter shows the descent stage as a bright spot, with smaller bright spots representing the experimental packages left on the moon. The enhancement brings out the tracks that the astronauts made during their moonwalks.

Forty-three years ago today, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin were on the moon for just 21 hours and 36 minutes, but thanks to a new NASA website, you can see how the lighting at their landing site changes over the course of the two-week-long lunar day.

This week, the team behind the camera on NASA's Lunar Reconnaissance Orbiter unveiled an online viewer that combines imagery at different sun angles for each of the Apollo landing sites, from sunrise to sunset. Such images have been released regularly for the past three years, but it's way cooler to see them presented with a slider that lets you see the shadows shorten and lengthen as the day wears on. You can also click buttons to add labels for the artifacts left at each site, to trace the paths of the astronauts' moonwalks, or just to get your bearings.

A murky view of the Apollo 11 site, captured by LRO just before lunar sunset, served as this week's "Where in the Cosmos" picture puzzle on the Cosmic Log Facebook page. I thought it was interesting to see the last rays of the day reflected off the very top of the Eagle lunar module's descent stage, producing a bright spot at the very center of the image. You can also see how the lunar module's shadow hitting the rim of the crater to the east of the landing site.

NASA / GSFC / ASU

This view of the Apollo 11 landing site was captured by NASA's Lunar Reconnaissance Orbiter just before sunset on the moon.

It didn't take long for Facebook followers to recognize what this mostly black picture showed. The first ones to register the right guesses — Mike Hardin, Brian McGraw, Wyatt Bates and James Aker — are eligible to receive celebratory pairs of 3-D glasses, courtesy of Microsoft Research's WorldWide Telescope team and yours truly. You can use your red-blue glasses to see 3-D views of the Apollo 11 site and lots of other space scenes.

The 43rd anniversary of any event is not usually that big of a deal, but today's "Dark Knight" shootings in Colorado left a lot of people looking for something positive to balance out all of the day's negativity. Apollo 11 provided that positivity, in 1969 and in 2012. I particularly liked the Twitter update from John Ryan: "News out of Colorado is grim, but today's also the anniversary of the first moon landing. Take heart, humanity can do amazing things, too."

No one knew that better than the late astronomer Carl Sagan. In Sagan's reflections on the Apollo missions, which endure in his book "Pale Blue Dot" as well as the Sagan Series of videos produced by Reid Gower, the sage marveled at the rare opportunity afforded by the Cold War space effort: "Once upon a time, we soared into the solar system. For a few years. Then we hurried back. Why? What happened? What was 'Apollo' really about?"

I can't watch the video without tears coming to my eyes. But at least they're not tears of grief.

More reflections on Apollo 11:

• Transterrestrial Musings: Evoloterra
• Bad Astronomy: What Apollo means to me
• Neil Armstrong still chooses to go to the moon
• Universe Today: The journeys of Apollo, on video

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 dwarf planet and the search for new worlds.