Binary_Earth-Size_Planets_Possible_Around-56d85d1e08bdf0208de1f49559c29cdaTwo Earth-size planets that orbit each other might exist around distant stars, researchers say. The solar system has many examples of moons orbiting planets; Jupiter and Saturn both possess more than 60 satellites. However, these moons are usually much smaller than their planets — Earth is nearly four times wider than its moon and more than 80 times its mass. Still, some moons are as large as planets. For instance, Ganymede, Jupiter’s largest moon, is larger than Mercury, and three-quarters the diameter of Mars. Also, moons at times are nearly as large as their worlds; Pluto’s largest moon, Charon, is about half the diameter of the dwarf planet itself. This raises the intriguing possibility that planets of equal size could orbit each other. More