Is There Life on Mars?

NARRATOR: Is there life beyond Earth? To find out, we might look no farther than the planet next door. Mars may be our best hope for resolving the ultimate mystery of creation.
STEVE GOREVAN (Honeybee Robotics): It is the one planet out there that is Earth-like enough that we can imagine that life might have taken hold on that world. 

CHRIS MCKAY (NASA Ames Research Center): If we go to Mars, will we find that, yes, the same events that led to life on Earth, happened independently on this other planet? 

PETER SMITH (University of Arizona): And if we find evidence on our very next planet, Mars, then you have to say that has to be so common across the Milky Way, across the universe, you know, that we are not alone.

NARRATOR: Mars has more in common with our world than any place we know of in the universe, but it's still a world away. Getting an astronaut there to search for life is beyond us. So, for now, we must resort to the next best thing, robots. Mars today is a busy place. Three satellites orbit it, three Landers ponder its surface. They're finding a wealth of clues.

STEVE SQUYRES (Cornell University): Holy smokes! I'm just blown away by this.

MICHAEL HECHT (Jet Propulsion Laboratory): When that first data comes down, the sense of astonishment is indescribable. Oh wow!

JOHN COATES (University of California, Berkeley): We would never have thought of looking for organisms like this on Mars.

NARRATOR: But they're also discovering that, in its past, Mars had some dark secrets.

SAMUEL KOUNAVES (Tufts University): Life can survive, survive in pretty harsh conditions, but there are limits.

ANDY KNOLL (Harvard University): Around four billion years ago, there was a cataclysmic event. 

DAN McCLEESE (Jet Propulsion Laboratory): And this was big. This thing went, wham, right into the planet.

NARRATOR: Four and a half billion years ago, two young planets emerged, both brimming with promise, but something went very wrong with Earth's twin. Is There Life on Mars?, up next on NOVA. PBS Airdate: December 30, 2008