We’re halfway through our candle-powered, latke-infused trip through the solar system. With the inner solar system and the asteroid belt behind us, here are some facts about the biggest of the bunch:
1) Four of the six biggest moons in the solar system are Jupiter’s, in order of size: Ganymede, Callisto, Io, and Europa. These moons are all easily seen with a small pair of binoculars. Ganymede is even bigger than the planet Mercury. Io is the most volcanic place in the solar system. Europa has more water than Earth does, which has many people wondering if there could be life there, too. Know what the other two biggest moons are?
2) Jupiter has four faint rings, which are made mostly out of dust. This is different from Saturn’s, which are mostly ice.
3) Not only would about 1000 Earths fit in Jupiter, but about 1000 Jupiters would fit in the sun.
4) Jupiter rotates in under 10 hours, the fastest of all the other planets, which is pretty impressive considering how huge it is (it’s two and a half times more massive than all the other planets combined). This is so fast that Jupiter is visibly oblate — flattened at its poles. The earth is oblate, too, but not as much as Jupiter is. Since Jupiter isn’t solid, it doesn’t rotate as a whole. The poles rotate slower than the area near the equator does.
5) The Pioneer 11 probe was the second to visit Jupiter, and flew within 27,000 miles of the tops of its clouds in December 1974. That’s the closest of any probe so far to fly past, Then it continued on to visit Saturn and eventually leave the solar system on its way toward the constellation Aquila, which it’ll reach in about four million years. In 1989, though, the Galileo probe entered Jupiter’s atmosphere and survived for about an hour before signals were lost.
6) When an object is orbiting another, the two actually orbit a common center of gravity called the barycenter, which is closer to the heavier object. Jupiter is the only planet to orbit a barycenter that is outside the sun.
7) In the summer of 1994, pieces of comet Shoemaker-Levy 9 hit Jupiter. This was the first time astronomers ever directly saw a collision between two objects in the solar system.
8) The famous Great Red Spot in Jupiter’s southern hemisphere is a storm that is about three times the size of Earth, and shrinking, and has been going for at least 400 years. It’s colder than the surrounding clouds, which means it is higher up in the atmosphere than those clouds.