Wikijunior:Solar System/Jupiter/Amalthea

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Amalthea is the third moon of Jupiter.

Contents 1 How big is Amalthea? 2 What is its surface like? 3 How long is a day on Amalthea? 4 How long is its orbit around Jupiter? 5 How would Amalthea's gravity pull on me? 6 Who is it named after? 7 How was it discovered?

[edit] How big is Amalthea?

Amalthea is not spherical like a ball, instead it looks like an asteroid. It has an average diameter of 172 km.

[edit] What is its surface like?

The surface of Amalthea has many craters. The largest crater, called Pan, is 100 km across and 8 km deep. Another crater, called Gaea, is 80 km across and twice as deep as Pan, being 16 km deep.

There are two mountains on Amalthea. They are called Mons Lyctas and Mons Ida.

[edit] How long is a day on Amalthea?

One day on Amalthea is equal to about half of an Earth day. One day is 11 hours, 57 minutes, and 23 seconds.

[edit] How long is its orbit around Jupiter?

One orbit around Jupiter also takes half a day.

[edit] How would Amalthea's gravity pull on me?

If you stood on the surface of Amalthea, you would weigh only 0.0018th of what you do on Earth. A one hundred pound person would weigh only 0.18 pounds on Amalthea!

[edit] Who is it named after?

Amalthea is named after a nymph who nursed Zeus, which is another name for Jupiter, with goat's milk.

[edit] How was it discovered?

Amalthea was discovered on September 22, 1892 by Edward Emerson Barnard, using the 36 inch (91 cm) refractor telescope at Lick Observatory.