Smallest Planet Outside Solar System Found SPAIN: April 10, 2008 MADRID - The smallest planet discovered outside our solar system has been found by Spanish scientists. "I think we are very close, just a few years away, from detecting a planet like Earth," team leader Ignasi Ribas told a news conference on Wednesday. The rocky planet, with a radius about 50 percent greater than the Earth's, circles a small red dwarf star 30 light years away in the constellation of Leo, said the scientists from Spain's Superior Council for Scientific Investigations (CSIC).