More than 3 billion years ago, Mars was a very different place.
It wasn't the rusty, dead seeming world we see today. Instead, lakes, rivers, and deltas likely covered much of the planet's surface. Thanks to previous NASA research, we know that at least some parts of the planet were, in fact, capable of supporting microscopic life as we understand it.
But who knows what once lurked within Martian waters.
Over the years, we've sent robotic missions to Mars to try to figure out the answer to this very question, and on Thursday, NASA announced that its Curiosity rover brought us another step closer toward figuring out if life once existed on the red world. Read more...More about Space, Science, Mars, Curiosity Rover, and Space Exploration