What Happened To the Martian Ocean and Magnetic Field? (theatlantic.com)

schwit1 writes with this story at The Atlantic that explores what may have destroyed the Martian atmosphere and ocean. The question of whether there is life on Mars is woven into a much larger thatch of mysteries. Among them: What happened to the ancient ocean that once covered a quarter of the planet's surface? And, relatedly, what made Mars's magnetosphere fade away? Why did a planet that may have looked something like Earth turn into a dry red husk? “We see magnetized rocks on the Mars surface,” said Bruce Banerdt, the principal investigator of the InSight mission to Mars, which is set to launch in March. “And so we know Mars had a magnetic field at one time, but it doesn't today. We would like to know the history—when that magnetic field started, when it may have shut down.”

Comments

Re:Global warming?

[serviscope_minor]

How could you, guys, miss this opportunity to refresh the fear in the hearts of your followers? If you keep burning fossil fuels, our planet too will become an airless desert devoid of life

Tell me, what's the carbon footprint of burning a straw man?

Re:This is basic planetary physics..

[RubberDogBone]

It's this exactly. Without a magnetic field, the solar wind dried out the planet and blew away a large amount of the already thin atmosphere. The low gravity didn't help any. The planet had a lot going against it from the beginning and was probably never a good place for complex life to appear. Barring some sort of cosmic change like how we got our moon and added a huge amount of iron and mass, Mars was always doomed to end up freeze-dried.

We currently have no way of fixing this problem so all the grand plans to terraform Mars won't work, unless they also restart the magnetic field, which we don't know how to do. It might take slamming a proto-planet into Mars to get things going again, which we can't currently do, and which would also make the planet essentially unusable for hundreds of millions of years, at least.

It also risks all kinds of other issues like disturbing other planets and introducing a lot of chaos into the solar system. But luckily we don't know how to knock planets into each other. And I suppose if we DID and we had that sort of tech, we would not need to bother with Mars. We'd just find a suitable planet elsewhere, which is probably easier.