Are humans alone in the Milky Way galaxy? To date, no one has an answer to the question, but US astronomers have found that Earth-like planets with enough water to support life could be fairly common. They ran 44 computer simulations of the planet formation process, and in each simulation one to four terrestrial (rocky, Earth-like) planets were formed.

The simulations were based on what is known about the late stages of the planet formation process. "It's hard to say we simulated exactly the conditions in which terrestrial planets form, but they are almost accurate,' said Sean Raymond, of the University of Washington, USA. Raymond accomplished the feat along with his colleague Thomas Quinn, and Jonathan Lunine, of the University of Arizona, USA.