Mars – rises as expected in the east but slowly. Despite the 30-hour orbit of Deimos, 2.7 days elapse between its rise and set for an equatorial observer, as it slowly falls behind the rotation of Mars. Because the orbit of Phobos is below synchronous altitude, the tidal forces from the planet Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two moons is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as
The Living Cosmos about the setting of the Earth and the events that have occurred on this planet. Subsequent chapters consider the origin of life on Earth, and the physical extremes to which life as adapted. In astrobiology, it pays to think “outside the box” and imagine how strange life might be or whether post-biological evolution is possible, where the basis is mechanical or computational. A chapter on evolution shows how it is affected by the cosmic environment. Possibilities of life in the Solar System are considered next, with emphasis on Mars, Titan, and outer moons harboring liquid water. Next is a summary