Jupiter

 Jupiter rotates the fastest of all the planets in the solar system, completing one rotation on its axis in just under ten hours. This causes an equatorial bulge that is visible through a simple telescope. Jupiter's upper atmosphere rotates differentially because it is not a solid entity. The polar atmosphere of Jupiter rotates more slowly than the equatorial atmosphere, by around 5 minutes. The planet is an oblate spheroid, which means that the distance between its poles and across its equator is greater than the distance between those two distances. The equatorial diameter of Jupiter is 5,764 miles greater than the polar diameter.

Jupiter is the biggest planet in the Solar System, and the fifth planet from the Sun. It is a gas giant with a mass that is slightly less than one thousandth that of the Sun but more than two and a half times that of all the other planets in the Solar System put together. After the Moon and Venus, Jupiter is the third brightest natural object in the Earth's night sky, and people have been seeing it since ancient times. It was given the name Jupiter after the Roman god and supreme deity.

When Pioneer 10 made its closest approach to Jupiter in December 1973, it became the first spacecraft to visit the planet. Since then, other robotic spacecraft have studied Jupiter, starting with the Pioneer and Voyager flyby missions from 1973 to 1979 and continuing with the Galileo orbiter in 1995. The New Horizons spacecraft visited Jupiter in 2007 by accelerating through its gravity and curving its course toward Pluto. Juno, the most recent spacecraft to explore the planet, orbited Jupiter in July 2016. The likely ice-covered liquid ocean of Europa is a future target for study in the Jupiter system.