Mars has surface water, but not enough. Ceres, the largest asteroid, might be 25% water. If we simply crashed Ceres into Mars, that could cover 33% of Mars with oceans up to 5900 meters deep. (Spherical projection by request.)
‘if we simply crashed Ceres into Mars”
yes, play the largest most destructive game of terraforming. Do it.
Terraforming, by definition, should be pretty destructive.
Also this just sounds incredibly cool.
this would fuck up mars’s orbit though (otoh that could be beneficial), and the blast would… i don’t even know. they’d probably knock into each other at a relative velocity of multiple kilometers per second?? i don’t think we actually know what the physics of an impact like that would even look like.
the problem with mars colonization really isn’t lack of surface water anyway. in a closed system like a pressurized habitat you can recycle basically all of the water, and there’s plenty of ice for the taking at the poles. the important part of terraforming is atmosphere, once you’ve figured that out you can worry about oceans. (although i guess crashing ceres into mars would probably give it an atmosphere made of water vapor? which would be moderately helpful for colonists so long as it was less than earth atmospheric pressure, which it… probably would be? again, what the hell does crashing planets together even look like)
(…actually the first problem with mars colonization is surface gravity, but if the colonists and their descendants don’t plan to visit earth it’s… probably fine)
Well Mars’ mass would obviously rise if you added all that water, so that should help.