NASA's Biggest Discoveries Of 2011

2011 was a big year for NASA. After thirty years of sending astronauts into space aboard its shuttle fleet, the agency officially retired the shuttle program after Atlantis completed its final mission in July.

But just because NASA isn't currently sending astronauts into space on its own (its crews have been hitching rides aboard Russian Soyuz spacecraft) doesn't mean the agency has stopped exploring the final frontier. Among the many NASA discoveries this year were near Earth-like planets, more evidence of water on Mars and a taller-than Everest mountain on an asteroid -- see even more in the slideshow below.

NASA administrator Charles Bolden said in a year-end video that the agency's office of chief technology is working on more than 1,000 projects "ranging across all technical areas, and levels of technical maturity." One of those projects, of course, is the development of the Space Launch System (SLS), a heavy-lift rocket announced in September that NASA plans to develop that aims to bring astronauts farther into space than ever before.

According to DiscoveryNews, NASA's budget for the 2012 fiscal year is $17.8 billion, which is $648 million less than last year and about $1 billion less than what President Obama requested.

"It's a golden age for science, and these missions are rewriting textbooks and inspiring the next generation who want to make their own discoveries," Bolden said in his year-end message.

We don't know what lies ahead, but if this year is any indication, 2012 should be full of exciting discoveries.

Check out the slideshow below to see the biggest discoveries from NASA in 2011. Be sure to vote for your favorites, and let us know in the comments what NASA discoveries most excited you. Anything you think we left out?

LOOK: NASA's Biggest Discoveries Of 2011