Red rain may be alien life seeded by a comet

A scientist believes that red rain that washed down in India during a two-month in 2001 is in fact organic life that was spewed into our atmosphere by a passing comet. His theory is doubted by the scientific establishment, but stranger theories about alien life have been proposed in the past.

While the comet theory is dubious, cChances are good that extraterrestrial life exists. Scientists have drawn up a list of the top 10 exosolar planets that could host life. We have no idea what such worlds would look like, but here are some renderings based on our current knowledge.

To give you an idea of the conditions necessary to host life, here is an interactive game that lets you build your own world. Or maybe it's just easier to create life just by thinking about it. Either that or make your own alien in a jar.