Mercury Spider Is a Spidery Crater on Mercury

Mercury Spider (picture above, credit: NASA) is not any known spider species on the Earth, but a unique geologic formation called the Spider sits at the center of the Caloris Basin[wiki] on Mercury. It was just revealed to the world in one of more than 1200 pictures taken from from the unseen side of Mercury by NASA's MESSENGER probe during a recent flyby on January 14. The spidery shape is "unlike anything we've seen anywhere in the solar system," said mission chief scientist Sean Solomon of the Carnegie Institution of Washington. The image showing what looks like a large crater with [25 miles wide] faint lines radiating out from it demonstrates that Mercury had volcanic eruptions millions of years ago and is a shrinking, aging planet. Link