sentences:  Planets above 10 Earth masses are termed massive solid planets, mega-Earths, or gas giant planets, depending on whether they are mostly rock and ice or mostly gas.The first super-Earths were discovered by Aleksander Wolszczan and Dale Frail around the pulsar PSR B1257+12 in 1992.The two outer planets (Poltergeist and Phobetor) of the system have masses approximately four times Earth—too small to be gas giants.