It’s Wednesday, so that means its time for another “Where In The Universe” challenge to test your visual knowledge of the cosmos. We’ve been busy searching hither and yon for unusual and unique astronomical images to see how well our readers are acquainted with the various locals across the universe. This week’s image is an unusual looking object. Just what is this thing? Could it be an asteroid, a wierd moon, or something you can find on Earth? Hmmm…… Ponder the image for awhile, and no peeking below before you make a guess. If only I could insert some music here, like the “Think!” theme song from the Jeopardy game show. I’ll have to talk to Fraser about that…
Have you made your guess?
And are you sure?
This is a Cassini image of Saturn’s unusual moon Hyperion. Hyperion is the largest highly irregular (non-spherical) body in the solar system. Scientists believe its very likely that is a fragment of a larger body that was broken by a large impact in the distant past. Is this a coral reef in space?
This sponge-like looking moon is a remarkable world strewn with strange craters and basically a strange surface. At the bottom of most craters lies some type of unknown dark material. Astronomers think the dark material might be only tens of meters thick in some places. Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might be mostly hollow inside — it may house a vast system of caverns. Wouldn’t that be fun to explore!
Or its low density could indicate that it is composed of water ice with only a small amount of rock and considerably porous. It’s very low density also seems to allow impacts to form deeper and sharper craters.
But unlike most of Saturn’s moons, Hyperion has a low albedo (.2 – .3) indicating that it is covered by at least a thin layer of dark material. Cassini data from 2007 indicates that this material is rich in organic molecules. Quite an interesting place, this Hyperion.
How did you do on this week’s challenge?