If any civilisation achieved space travel in the past million years there should still be artifacts on any of the moons or planets that they visited.
If you have a global conflict and you need another home quickly, Mars is the obvious choice. Provided that you have the right technology it can provide all the resources you need.
Project Orion - the US plan to develop a space ship the size of an ocean liner powered by small nuclear bombs - demonstrates how easy it is to transport people and resources to Mars, provided you don't mind leaving a little bit of radioactivity behind.
The Vortex Fusion Drive demonstrates how easily a more sophisticated fusion engine can provide the necessary drive energy.
The US's sudden loss of interest in the Moon as a target for exploration, and the transfer of resources to the planet Mars suggests that others are thinking along the same lines. It also explains why the pictures comingback from Mars are censored before release. You don't censor informationunless you expect to find somthing that you want to keep hidden!
But the pictures of the Martian surface that have survived the censor do reveal enough to evaluate the possibility that someone has attempted toterraform the surface of Mars in the recent past. The censors are technologists,looking for anything that they can identify as a potentil indicator of technology, but there are many more artefacts of life that can be identified!
The atmosphere of Mars is thin, but its South Pole is a depression 7 miles deep. It does not take rocket science to deduce that if the atmosphere is thin over most of its surface- equivalent to the top of Everest, then 7 miles lower down the atmosphere should be much thicker. It is this polar depression where any trace of life should be found.
This information is copyright Peter Thomson 2001-2004