S/2010 J 2

In 2012, the astronomers claim to have pinned down details of Jupiter’s smallest known moon — a tiny space rock which is barely 2km wide. The moon, known as S/2010 J 2, was discovered along with a fellow shrimpy satellite called S/2010 J 1 in 2010. After almost two years of observation, scientists have found that S/2010 J 2 has a diameter of about 2km. Their discovery brought the number of documented Jovian moons to 67.