Is there life on Mars, Venus, anywhere else?? The proximity of the Earth to the sun, the make-up of the Earth's crust (silicate mixtures, presence of water, etc.) and the size of the Earth suggest we may be unique in our own solar system, at least. Mars is smaller, farther from the sun, has a lower gravitational field (which would keep the atmosphere from escaping into space) and does show evidence of running water sometime in its past. If life did start on Mars, however, there appears to be no life (as we know it) today. Venus, the second planet, is closer to the sun, and appears similar to Earth in many respects. Carbon dioxide build-up has resulted in a "greenhouse planet" with strong storms and strongly acidic rain. Of all planets in the solar system, Venus is most likely to have some form of carbon-based life. The outer planets are as yet too poorly understood, although it seems unlikely that Jupiter or Saturn harbor life as we know it. Like Goldilocks would say "Venus is too hot, Mars is too cold, the Earth is just right!"
This is the end of the preview.
access the rest of the document.