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 shaped like a circle, 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 m 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.