About this world
MOA-2008-BLG-310L b is a Neptune-like planet orbiting MOA-2008-BLG-310L, a star 25.1 thousand light-years from Earth. It is about 5.2 times the size of Earth (its size estimated from its mass) and holds 23 Earth masses.
At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2009 by microlensing with MOA. A foreground star's gravity magnifies a background star; a planet adds a blip.