I have always considered the jets of matter that are accelerated from the poles of supermassive black holes to be pretty damn scary. Particles in those streams approach the speed of light and stretch for many thousands of light years, they must absolutely decimate anything that is unlucky enough to be in their path

The problem is mars has already lost a lot of its atmosphere, it’s a big job to replace it and we already know it’s a leaky boat. Plus even if it did have an atmosphere everything would be irradiated. We can certainly move about on it’s surface but it’s never going to be like earth.

Well mars once had an atmosphere and liquid water on its surface, if we answer why it doesn’t now we might understand why it’s less suitable than one of the ice moons. Mars is smaller and less dense than earth, it also doesn’t have a magnetosphere. This means that it doesn’t have a protective shield against solar wind which blows away any atmosphere. Also because Mars’s gravity is low it doesn’t hold on to an atmosphere as well as the earth. We could terraform mars but it would still be bombarded by solar winds.

I think if we explore these moons with potentially liquid sub surface oceans and find that there is no life but there is an environment capable of sustaining life. We should consider seeding these places. Imagine they could be locations that we can fill with life there isn’t any other place in our solar system that could potentially support such large ecosystems. Mars never will but we could create giant resources of terrestrial organisms.