last week that they have discovered the smallest extrasolar planet ever detected. Just seven-and-a-half times the mass of Earth, the newly identified planet is in orbit around a star 15 light-years away. The artist's conception above depicts the new planet as a hot, rocky and geologically active world bathed in red light from its parent star Gliese 876. Scientists estimate surface temperatures could reach between 200 and 400 degrees Celsius.