A multi-media simulation showing a "super-Earth" more than 20 light years away. (Martin Bernetti/AFP/Getty Images) There’s only one Earth, but scientists that scan the skies for alien planets have found plenty of “super-Earths.” In astronomer-speak, super-Earths are bigger than Earth but smaller than Neptune. Newresearchpublished last week in the journal Science says the discovery of Gliese 486 b could help us betterunderstandour own world. Trifon Trifonov, a postdoctoral research associate at the Max Planck Institute for Astronomy, led the research team. His team uncovered a planet orbiting a red dwarf star about 26 light-years away, which is close by in the scale of the universe.