May 17 - Jupiter's Belts Discovered!

Posted on May 17, 2021

Key points

This is an update of my post published on May 17, 2010:

You’ve seen pictures of Jupiter, right? Those reddish-brownish stripes, the Great Red Spot, all those swirling clouds?

Of course, there was a time, before telescopes, when Jupiter was just a bright “star” in the sky and none of these details were known.

On this day in 1630, Jupiter’s belts were first discovered by Jesuit astronomer Nicolas Zucchi.

(Notice that the light-colored stripes are usually called “zones” and the darker-colored stripes “belts”; the Great Red Spot, which is associated with the Southern Equatorial Belt, is sometimes called the belt buckle.)

In 2010, an amateur astronomer discovered that Jupiter’s Southern Equatorial Belt had disappeared.

You see, earlier that year Jupiter went “behind” the Sun, from Earth’s point of view, and we weren’t able to observe it for a few months. When it emerged from the Sun’s glare, the belt was gone.

Yes, that’s right–Jupiter had a belt buckle with no belt!

Don’t worry, though. The belt has since reappeared, and apparently the belt has disappeared and reappeared several times. Scientists guess that, when Jupiter’s temperatures drop a bit because the planet is moving farther away from the Sun (because planets circle the Sun in slightly oval orbits rather than perfectly round ones), the cooling temperatures cause the dark chemical clouds that make up the belt to sink lower into the atmosphere. When the belt sinks, light clouds close in above it and hide it from our view. Of course, eventually Jupiter gets a bit closer to the Sun again, warms up, and voila! Its belt reappears!

Quick Quiz on Jupiter

1. Who was Jupiter named after?

A. the Greek god of war
B. the king of Greek gods
C. the Roman god of war
D. the king of Roman gods

2. How many moons or satellites does Jupiter have?

A. 2
B. 16
C. at least 63

3. Does Jupiter have rings?

A. Yes
B. No
C. Sometimes

4. Jupiter’s Great Red Spot is most like a ____.

A. satellite
B. dust storm
C. hurricane

5. How large is the Great Red Spot?

A. the size of Earth’s moon
B. the size of the Earth
C. more than twice the size of the Earth

6. Counting out from the Sun, Jupiter is the ____ planet.

A. third
B. fourth
C. fifth
D. sixth

7. In size, Jupiter is the ____ planet.

A. largest
B. second largest
C. smallest

8. Jupiter is considered one of the ____.

A. inner planets
B. gas giants
C. rocky planets

9. The first person to spot Jupiter’s moons was ____.

A. Galileo
B. Sir Isaac Newton
C. Copernicus

10.The adjective form of Jupiter’s name is ____.

A. Jupiterian
B. Jovian
C. Jupiterial

ANSWERS: 1.D – 2.C – 3.A – 4.C – 5.C – 6.C – 7.A – 8.B – 9.A – 10.B

Play Around in the Solar System

Do you know how much you weigh? On Earth, that is! Find out how much you would weigh on Jupiter and the other planets.

Did you know that, if Jupiter were the size of a basketball, the Earth would be a bit smaller than a pingpong ball?! Learn about the relative sizes and distances of the planets in the solar system by using this conversion tool. (If you want, you could make a scale model!)

How old would you be on Jupiter? This gigantic planet is so far from the Sun (compared to the Earth), that one Earth year is just a fraction of a Jovian year. Find out your age here.

Can you imagine living on one of Jupiter’s moons? Your nighttime sky might look something like this:

Europa is one of Jupiter’s most interesting moons, with the possibility of an ocean under the surface ice, and even life. A long time ago, in1903, an artist painted this picture of Europa as a much warmer, full-of-life moon…