The earth revolves around the sun. Mars revolves around the Sun. Venus, Mercury, Neptur, Uranus, and Saturn too. The moon and the International Space Station revolve around the Earth. But with the giant planet Jupiter, everything is somewhat more complicated.
When in outer space a less massive body revolves around a more massive one, the light one does not describe ideal circles around the center of the heavy one. In fact, both rotate, and the center of mass of both bodies serves as the center of this rotation. If the difference in mass is very large – as, for example, between our planet from the Sun – then the center of mass is located inside a more massive body, at a negligible distance from its geometric center. But if the mass of two bodies is comparable, then the center of mass can be located in space outside both bodies.
Jupiter’s mass is 2.5 times the mass of all other objects in the solar system. The mass of Jupiter is 1 898 600 000 000 000 000 000 000 000 kg, and the mass of the Sun is 1 990 818 700 000 000 000 000 000 000 000 kg, with a difference of 1000 times. Such a relatively small difference in mass displaces the point around which both the Sun and Jupiter move, mutually attracted by gravity. This point is, according to calculations, at a distance equal to 7% of the solar radius from the surface of the star. In other words, Jupiter, the only one of the planets in the solar system, revolves around a point in space that does not lie inside the sun, but outside it.