Up to a certain point in the NASA video below, we could be looking at a very young Earth. Our planet looked just like this until around 433 million years ago, when plants first started colonizing the land.
Then, on Mars, something happened . . . no one is sure exactly what or when it occurred, but it made all the difference.
What Happened to Mars’ Water?
It wasn’t a big dust storm – we just don’t know what happened to the water and the thicker atmosphere that made all that open water possible.
Now, not all scientists are on board with the warm Mars envisioned in this video, per the Jet Propulsion Lab. Some think Mars has always been cold (its average temperature today is -67° F/-55° C), with lots of ice underneath the surface that occasionally would melt for some reason and gush out as liquid water.
Either way, the planet would have needed a thicker atmosphere at that time to keep the water from evaporating before it left its mark (PDF) on the land.
If you’re having trouble visualizing that, imagine somehow dropping the Atlantic Ocean over the Moon, which has no atmosphere.
The Atlantic Ocean is really big. Doesn’t matter – space is bigger, and really, really dry.
Unlike the Moon, Mars does have an atmosphere and weather today, as these arctic Martian clouds show.
However, Martian air today can’t keep liquid water from freezing and/or evaporating at the surface. Whatever water is left on Mars, therefore, is locked up in the soil, the ice caps and perhaps underground.
The disappearance of the lakes, oceans and rivers probably didn’t happen after an asteroid impact or any other sort of massive disaster. The biggest geologic changes happen slowly and through many small changes, so the old water bodies of Mars probably did disappear gradually, just as in the video, whether the planet was once warm or has always been cold.
I like to think that whatever happened on Mars was something ordinary that always happens on planets like that and that the really unusual event – development of the sort of supportive world that was ideal for life – happened on Earth.
If you compress 4.6 billion years into 60 seconds, it does seem pretty remarkable:
That’s “banded iron formations,” or BIFs, by the way.
Since iron is a pretty common element on the Rusty Planet, I’ve also wondered if Earth’s formation of these iron bands is a clue of some sort to what might have happened to Mars’ water.
Scientists consider terrestrial BIFs as fossil evidence of life in very ancient times. I wonder if BIFs might also show that life and its geologic setting are incredibly closely linked. Did life that would produce oxygen and ultimately cause the removal of much of the water’s dissolved iron not evolve in Mars’ oceans?
Is that what changed everything? If so, how?
I mean, if a butterfly can flap its wings in Beijing and cause a hurricane in the West Indies, or whatever, what chaotic interactions might result from an overabundance of iron in a global water system over geologic time?
Is that a truly dumb question, or is it more along the lines of “hey, did you ever notice that the coasts of South America and Africa line up”?
Who knows… .
Mars Exploration Ongoing
In any event, we have just launched MAVEN, one of many exploratory missions, in hopes of learning more about Mars’ atmosphere, and India’s Mangalayaan Mars orbiter is expected to leave Earth orbit for Mars on December 1.
Of course, no one mission or group of missions will come up with “the answer” to the question of what happened to Mars’ water. It will still be a puzzle even after we have first landed and colonized the planet.
But someday we will know what happened.