Saturn's Sponge Moon Hyperion
Why does this moon look like a sponge? To better investigate, NASA and ESA sent the Saturn-orbiting robotic spacecraft Cassini zooming past Saturn's moon Hyperion.
One of the images beamed back to Earth is this one, raw and unprocessed. Visible, as expected, are many unusually shaped craters with an unusual dark material at the bottom. Although Hyperion spans about 250 kilometers, its small gravitational tug on Cassini indicates that it is mostly empty space and so has very low surface gravity.
Therefore, the odd shapes of many of Hyperion's craters are thought to result from impacts that primarily compress and eject surface material -- instead of the more typical round craters that appear after a circular shock wave that explosively redistributes surface material.
Image & info via APOD
On a second note, APOD celebrated 20 years yesterday (16.06.2015)
Happy B-day APOD!
http://apod.nasa.gov/apod/ap150616.html
#NASA #ESA #APOD #Cassini #space
Fact: this moon is made of cheese.
ReplyDeleteSomeone's already fracked it.
ReplyDeleteAstronomy is another one of the branches of science in which most questions answered are a new question revealed. In this case, I wonder why Hyperion exhibits this material ejection behaviour when impacted.
ReplyDelete