Mars Express Radars Mars

It’s one of those no-brainer ideas: that water once existed on the surface of Mars.  All you have to do is LOOK at the planet and you see evidence of something that flowed across the surface.  There are washed out valleys, what look like river canyons, and regions that look like the shores of ancient oceans. If we had geologists (areologists?) on the planet, they’d make short work of determining what it was that flowed across the planet’s surface by taking surface samples and analyzing them.

Well, we don’t have people on Mars — yet. But, we do have spacecraft orbiting the planet and sitting on its surface sending us back all manner of daily data about this rusty, red desert world. The European Space Agency’s Mars Express mission has a radar instrument called MARSIS that bounced signals from the surface back to its detectors. The data in those signals told planetary scientists that at least one part of Mars is covered with sediments that were probably laid down on the floor of an ancient ocean.  The sediments contain minerals and possibly some ices that identify the area as the site of an ocean that existed perhaps 3 or 4 billion years ago, when Mars was very young, and possibly warmer and wetter than what we see today.

The oceans probably didn’t last very long; their water frozen into place, or vaporized and escaped through the planet’s thin atmosphere to space. So, the chances for life to form in those oceans were likely pretty thin.  Life or no life, the evidence for water flowing on the Martian surface in the dim recesses of history is pretty exciting. Now, the questions remain: where did all the water go and was there ever a chance that Mars harbored life?  Stay tuned!

Speaking of staying tuned, have you checked in on this month’s “Our Night Sky” at Astrocast.TV?  If not, why not?  Learn what’s up in the February skies!  You might find Mars…