SANTIAGO, Chile, April 25 Astronomers in Chile have discovered a planet they described as the "most Earth-like planet outside our solar system." The UK Express reported that planet Gliese 581 C could support life because its temperature is similar to Earth's and it could have liquid water."Because of its temperature and relative proximity, this planet will most probably be a very important target of future space missions dedicated to the search for extra-terrestrial life." Xavier Delfosse of France ' s Grenoble University told the Express. "On the treasure map of the universe one would be tempted to mark this planet with an X." Swiss, French and Portuguese astronomers found the Gliese 581 C while measuring wavelengths of light at the European Southern Observatory in Chile.Gliese 581 C is 20.5 light-years from Earth.Copyright 2007 by UPI