Enceladus is a moon of Saturn.
How big is Enceladus?
Enceladus measures 498.82 km across.
What is its surface like?
The surface of Enceladus has a great deal of variety. Pictures taken by Voyager 2 revealed at least five different types of terrain, including several regions of cratered terrain, regions of smooth, young terrain, and lanes of ridged terrain that often border the smooth terrain. The picture also revealed cracks that crossed the cratered and smooth terrain.
The smooth plains have very few craters, indicating that they are very young. This means that there are cryovolcanoes on the surface, or something else that renews the surface.
When the Cassini spacecraft flew by on February 17 and March 9, 2005, it revealed even more detail about the surface of Enceladus. The smooth regions that Voyager 2 saw now had many small ridges and scarps, while the old cratered regions had many fractures.
How long is a day on Enceladus?
One day on Enceladus is equal to 1.37 Earth days, or one day, 8 hours, and 53 minutes. This is the same amount of time it takes to complete an orbit around Saturn. As a result the same side of Enceladus is always facing toward Saturn. When the orbit and the rotation times match like this, it is called synchronous rotation: Earth's Moon is another example.
How would Enceladus' gravity pull on me?
If you stood on the surface, you would only weigh about 1/10 of what you do on Earth. This is because, although you have the same mass in either place, Enceladus has much less mass than the Earth.
Who is it named after?
Enceladus is named after a Gigantes in Greek mythology. He was defeated by one of Zeus' thunderbolts, and placed under Mt. Etna. The fire from the mountains is said to be his breath, and the rumbling of the mountain is said to be from him rolling around inside.
The name, as well as the names of the other moons of Saturn, was suggested by John Herschel, son of William Herschel, in his 1847 publication Results of Astronomical Observations made at the Cape of Good Hope.
How was it discovered?
Enceladus was discovered in 1789 by the English astronomer William Herschel.