The Asteroid Belt in Lowell Was Right!

The asteroids are the scattered remnants of the fifth planet, called by the Martians Perago, and destroyed when Mars was at the height of her power, about the time humans were discovering agriculture. From Martian evidence, the people of Perago were much like earth’s naked mole rat. They communicated telepathically at very short range, and had a combinatory intelligence - that is, they were only sapient when 4 or more were in close proximity. Larger gatherings than 7 were unstable, and would fall apart after short periods. The Martians claim that there are Peragoans still living in the asteroid remnants of their home world, but this has been dismissed by scientists as impossible.

Ceres

Ceres is by far the largest asteroid, and made up primarily of salt water, frozen into ice, from the seas of Perago. It holds the largest population of the asteroids as well, approximately equal portions of Martians, Mars Humans, Galileani and Earth Humans. The ice is melted as needed for water, creating honeycomb caverns all over the surface, filled with air. The surface is covered with solar panels to provide the power required.

Pallas

Pallas is the second largest asteroid, and made up of core materials of Perago - mostly nickel iron. Pallas has been mined by Martians, Galileani, and now Humans since soon after Perago was destroyed. There is a significant transient population, as well as a large permanent population, mostly miners, of all three peoples.

Others

There are scattered populations on several other asteroids as well - gems and rare earths are mined in several, as well as nickel and iron, and more are being mapped all the time. The remnant Peragoans are said to live in these scattered rocks and iceballs.