Jupiter is the fifth planet from our Sun and the biggest of the close planets in our solar system. It has a thick atmosphere of hydrogen and helium, with small amounts of methane and ammonia. These gases form the blotches and stripes you see on the planet, as well as the Great Red Spot, an oval of counter-clockwise moving storms four times larger than Earth.
Jupiter’s fast rotation causes the atmospheric layers to move rapidly, creating jet streams that separate dark belts from bright zones over long stretches of the sky. The vivid colors you see in the clouds are largely due to plumes of sulfur and phosphorus, which rise from the planet’s warmer interior.
The gas giant’s elliptical orbit means that its distance from Earth fluctuates, from 741 million miles (460 million km) when it is closest to us, to 601 million miles (968 million km) at its furthest. The planet is at its most brilliant when it is closest, making it a great target for evening stargazers.
Like all the planets in our solar system, Jupiter orbits a center of mass called the Sol-Jupiter barycenter. Since the Sun is more massive than Jupiter, they don’t travel in a perfect circle around each other, but instead share an orbital plane with equal size and mass. This wobble causes the seasons on Earth, but on Jupiter, whose axis is tilted only about 3 degrees from the Sun, seasonal changes are very slight.