Mars: our (once) watery neighbor?

NASA’s Mars Curiosity rover—and its tracks.
Image credit: NASA/JPL-Caltech
Read more here.

With the Mars Curiosity rover roving all over the Red Planet (and sending off some very entertaining tweets as it does), it seems appropriate to revisit astrophysicist Maria Sundin’s talk at TEDxUniversityofGothenburg on water, and its importance to our planet—as well as others.

From the talk:

“Looking at our neighbor, Mars—It is today a cold, dry desert planet. It’s smaller than the earth. But during the time that life arose on Earth—originated here—Mars was very different. It had a huge ocean on the northern hemisphere; it had an atmosphere.

…If we talk about life in the universe, people usually want a big spaceship landing right outside there so we can, you know, try to communicate…but I would almost be just as intrigued if I found a dead bacteria or something very small and lifelike on Mars because that could give us the key to whether life originates if you have a place where the conditions are favorable.

The reason why Mars has changed so much is that it’s smaller than the earth. The lesser gravity means that Mars has been unable to keep its atmosphere, so it’s very low pressure on the surface. If you were to pour out a glass of water on the surface of Mars, it would just evaporate instantly.

But there has been lots of water there …so, just imagine this old neighbor planet—it has had oceans; it has had rivers; it’s been a very different world. So worlds can change.”