Mars is very aptly nicknamed “The Red Planet.” Aside from some dry ice polar caps, the landscape on Mars is cold, dry, and rocky. However, that wasn’t always the case. Four billion years ago Mars was covered in water. It had a much thicker atmosphere that kept the planet warm enough for rivers to flow and for liquid water to stand. On November 18, NASA will be launching the Mars Atmosphere and Volatile EvolutioN (MAVEN) which will try to determine what happened to the atmosphere on Mars.
What happened to the water of Mars is something I’ve wondered for many years. IFLS actually understates the nature of Mars ice caps; not only are they compose of dry ice, but there’s a significant amount of water ice contained in those ice caps.
But beyond that, I do have my own theory on what happened to Mar’s water and atmosphere.
Back a couple decades ago, I was looking at images and maps of Mars.
After staring at these maps for I don’t know how long, and I began to wonder if the reason the southern hemisphere was more cratered was because of elevation and water erosion, or was it because the planet had undergone more extensive bombardment in its southern hemisphere.
That got me to wondering, if Mars had undergone an intense bombardment of asteroids, could ever be enough kinetic energy in that to push large amounts of water and soil from Mars into orbit?
In other words, one or more asteroids hit Mars and the energy from that cast a large amount of Martian water, atmosphere and soil into orbit, and the Martian moons, Phobos and Deimos, were born from the leftovers.
Over the years, I’ve looked around to see if anyone else this this is possible. I have yet to read anything suggesting that, but one bit of information in support of my idea is that the Martian moon Phobos, is most likely comprised of a significant amount of water ice.
One day we’ll know for certain what happened to the water of Mars, but until then, it’s fun to speculate.