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Jupiter facts

Facts About Jupiter: A Quick Tour of the Solar System’s Largest Planet

Diamond rain? More than 60 moons?! Learn all about these strange facts and more as we take a trip to the solar system’s largest planet, Jupiter.

Big, But Fast

The gas giant Jupiter is big. Really, really big. If you piled up all of the other planets in the solar system, Jupiter would still be 2.5x more massive than that. Some astronomers call it a “failed star” since its mass is closer to the sun than the other planets.

Although we tend to think of Saturn as the only planet with rings in our solar system, Jupiter has a thin ring system, too! The dusty rings are tough to see, though. Astronomers believe the Jovian rings are the result of small meteors striking the planet’s moons.

Despite its size, Jupiter is also the fastest planet. It spins much faster than earth, taking just 10 hours to rotate completely on its axis. The rapid rotation generates incredible magnetic fields and even changes the shape of the planet from a perfect sphere to a slightly flattened ball.

Although it has the shortest day in the solar system, it still takes Jupiter almost 12 Earth years to make a full trip around the sun. Also, because of the very slight tilt of its axis, Jupiter does not experience seasons. The weather is always the same–non-stop storms!

Jupiter’s Many Moons

Jupiter had a major influence on our early understanding of the solar system. In 1610, Galileo discovered the 4 largest moons of Jupiter. When he realized that these objects were orbiting another planet, it was evidence that the Earth was not, in fact, the center of the universe.

Io, Europa, Ganymede, and Callisto are still known as the Galilean moons. Ganymede is bigger than both Mercury and Pluto, and astronomers believe there is liquid water underneath its icy surface. Europa may also be covered in a massive ocean. Meanwhile, Io is essentially all volcanoes.

These planet-like moons are joined by many more smaller moons. The exact number is tough to pin down, since new moons keep getting discovered as we send spacecraft to explore Jupiter. Some estimates put the number at over 200! But astronomers can agree that there are at least 60 more micro-moons orbiting the planet. Currently, NASA lists 79 official Jovian satellites.

Massive Hurricanes and Diamond Rain

The most distinctive feature of the planet is the famous Great Red Spot. Amid the moving bands of storms is a darker red oval. It’s basically a massive hurricane with 400 miles an hour winds that have raged for centuries! Imagine a storm 3x bigger than Earth–that’s the Great Red Spot.

It’s possible that the immense atmospheric pressure on Jupiter might cause it to rain liquid diamond. The clouds are mostly made of ammonia, hydrogen, and helium. The deeper into the planet you go, the more intense the pressure becomes. The hydrogen in the atmosphere becomes a liquid.

We think that there’s a solid core in there somewhere, but no instruments made on Earth could survive the trip to find out..

Deana Adams

When Deana Adams was a kid, she begged her parents for a backyard telescope every birthday and Christmas until they finally caved. As an avid amateur stargazer, she memorized the constellations and hunted for the planets, collecting facts about astronomy the way other kids collected baseball cards or Barbies.

Deana is a contributing writer at NightSkyGaze. She still has her very first telescope.