Jupiter's mass. Illustration of the planets of the Solar System on a weighing scale, with Jupiter outweighing all the other planets put together. Jupiter's mass is about two and a half times that of the Solar System's other planets combined. Although called a planet, it is technically a brown dwarf - a star that is too small to self- ignite. Jupiter is over three times further from the Sun than Earth is. A year on the planet lasts about 12 Earth-years, while a day lasts only 10 hours.