What Makes a Planet Livable? Five Things Scientists Look For
Since 1995, astronomers have been hunting in earnest for possible havens for life outside the solar system. So far, they’ve detected more than 550 extrasolar planets, or exoplanets. Another 2,000-plus possible planets are waiting in the wings for confirmation. Researchers are working on ways to identify a “potentially Earth-like” planet – even if it isn’t an identical twin. One group, led by Washington State University astrobiologist Dirk Schulze-Makuch, has proposed a way to rate any planet’s potential habitability and how similar some of its basic properties are to Earth’s. Based on the rating systems, published in a recent issue of the journal Astrobiology, there are five main clues the team looks for.