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The Year in Space: Hello to Mars ... farewell to Neil Armstrong

Retrace the highlights of space exploration in 2012 — including a landing on Mars, a farewell to the first moonwalker, and a beautiful "Black Marble."

Every year marks beginnings and endings, but when it comes to space exploration, 2012 ranks as a big year for both starts and stops. SpaceX opened what could be a new era for commercial spaceflight. NASA's Curiosity rover began what could turn out to be a decade-long mission on Mars. First moonwalker Neil Armstrong, arguably the world's best-known (and most private) astronaut, passed away. So did Sally Ride, America's first woman astronaut. And after 30 years of service, the space shuttle fleet finally settled into museum retirement.

We've put together a slideshow that hits the off-world highlights of the past year. We've also put together an unscientific poll that lets you choose the top story for 2012 and the top trend for 2013. Without further ado, here's our 16th annual "Year in Space" roundup:

Top stories of 2012
It's always tough to limit the list to five, so I'm including an "other" category in this bunch. Please tell me in your comments why you think I'm underplaying or missing your favorite outer-space story.

• Curiosity goes to work on Mars: After a long cruise and seven minutes of terror, NASA's nuclear-powered Curiosity rover was dropped onto the Red Planet's surface in August to determine whether Mars ever had the chemical requirements for life. Curiosity soon figured out that it landed in the midst of an ancient riverbed, and started sniffing out evidence of complex chemicals. This whole rover thing is working so well that NASA wants to do it again in 2020.

• Godspeed, Neil Armstrong: Just as Curiosity was settling in for the long haul, Apollo 11 commander Neil Armstrong died of complications from heart surgery in August, at the age of 82. A nation mourned, and Apollo 13's Jim Lovell said Armstrong's passing "closed the book on the Camelot of manned spaceflight." The farewell to Armstrong came just a month after Sally Ride died at the age of 61, after a battle with pancreatic cancer. After her death, revelations about her complicated personal life stirred up controversy.

• SpaceX delivers the goods: The company founded by dot-com billionaire Elon Musk a decade ago finally sent a Dragon cargo capsule to the International Space Station during a demonstration flight in May, marking the space station's first commercial delivery. SpaceX did it again in October, turning what once seemed like science fiction into the new routine. SpaceX is also among three ventures getting a total of $1.1 billion to develop new spaceships capable of carrying astronauts to and from the space station.

• Farewell tour for shuttles: After months of decommissioning, all three of the retired space shuttles completed their final journeys to their new museum homes. Discovery went to the National Air and Space Museum's annex, near Washington. Endeavour made a cross-country flight and cross-town trek to the California Science Center in Los Angeles. Atlantis was towed to Kennedy Space Center's visitor complex. And the prototype shuttle Enterprise was shifted from the Smithsonian to New York's Intrepid Sea, Air and Space Museum. In October, the Enterprise got a buffeting from Superstorm Sandy.

• Asia's space efforts rise: China reached new milestones in June by putting its first woman in space, on a mission that marked the Chinese space program's first crewed docking. The test marked a significant step toward setting up an orbital space station, which China wants to do by 2020. In December, North Korea put a satellite in orbit, stirring new concerns about the isolated country's intentions. (The satellite went into a tumble, and all the signs suggest that whatever orbital mission it had ... has failed.)

• Other stories: June's transit of Venus marked the last event of its kind until 2117. NASA's Messenger probe detected water ice on Mercury. NASA's twin Grail probes arrived in lunar orbit, did their job and crash-landed on the moon, all in the course of a year. In November, a total solar eclipse wowed skywatchers, including yours truly.

Top trends of 2013
For some reason, my crystal ball is showing a fuzzy picture when it comes to the next year's trends. Maybe that's because we're in the midst of a hiatus for U.S. human spaceflight, or maybe I'm just missing the big picture. It's up to you to tell me in the comment section what I'm forgetting. 

• Commercial astronauts take off: Virgin Galactic is closing in on the first powered flight of its SpaceShipTwo rocket plane, and commercial test pilots could soon break the space barrier for the first time in more than eight years. Under the most favorable circumstances, it's even conceivable that paying passengers could be going on Virgin Galactic's suborbital space tours by the end of 2013. But we've heard all this before ... 

• Space gets a business case: In November, Uwingu announced that it would launch a planet-naming project to raise money for researchers (and investors). Meanwhile, two dozen teams are jockeying for position to send rovers to the moon and win a piece of the $30 million Google Lunar X Prize. Crowdsourcing is powering space elevator ideas and DIY satellite projects. Planetary Resources has a plan to make enough money building space telescopes to fund an asteroid-mining venture. Will spacey ideas like these actually pay off in 2013? Stay tuned.

• Earth's twin detected at last: Astronomers are already detecting planets in cosmic environments that just might support life as we know it. But they're aiming for an even more ambitious goal: to find Earthlike worlds, in Earthlike orbits, around sunlike stars. As NASA's Kepler mission builds up its database, will the data point to such planets? Or is it still too soon? 

• Will NASA change direction? NASA is working on a next-generation heavy-lift rocket and a heavy-duty spaceship, with the aim of launching test flights as early as 2014, crewed flights in 2021, and a human mission to a near-Earth asteroid in the mid-2020s. But some experts are questioning whether NASA is on the right path. Tight budgets for planetary science add to the uncertainty, particularly with a fiscal cliff looming. Will there be more shifts (or downsizings) in America's space vision? 

• Comets in the spotlight: Two comets have the potential to wow Northern Hemisphere observers in 2013: Comet PANSTARRS in March, and Comet ISON in November. It's too early to tell whether these alien visitors will live up to high expectations, but if the cosmos plays its cards right, the brightest highlights of the coming year may well turn out to be these "stars of wonder."

• Other trends: The sun is due to reach the height of its 11-year solar activity cycle in 2013, although so far this solar max is looking relatively wimpy. NASA's MAVEN mission to Mars is set for launch in November. Meanwhile, China is planning to launch another set of astronauts into orbit, as well as a robotic moon rover.

Cast your votes using the unscientific Live Poll ballots above, and feel free to register a write-in vote by leaving a comment below.

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.