SOURCE: National Geographic News
April 6, 2005
A new study of known planetary systems outside our solar system gives a theoretical boost to the search for extraterrestrial life. Researchers in England say that half of the systems could harbor habitable, Earthlike planets.
Barrie Jones, an astronomer at the Open University in Milton Keynes, England, co-authored the new study. He said, "We were particularly interested in the possible survival of 'Earths' in the habitable zone."
"This is often called the Goldilocks zone—where the temperature of an 'Earth' is just right for water to be liquid at its surface. If liquid water can exist, so could life as we know it."
The location of a system's habitable zone depends on how bright and hot the that system's star is. The zone can shift over the eons as the star ages and becomes brighter and hotter.
Jones collaborated with Open University colleagues Nick Sleep and David Underwood. The team used computer models to map the habitable zone in some 130 known exoplanetary systems—star-planet formations found outside our solar system.
Read more: http://news.nationalgeographic.com/news/2005/04/0406_050406_exoplanets.html