How did Iapetus get that weird ridge?
(PHYSORG)- But it's only been five years since the arrival of high-resolution Cassini Mission images of Saturn's bizarre moon Iapetus that the international planetary community has pondered the unique walnut shape of the large (735 kilometer radius) body, considered by many to be one of the most astonishing features in the solar system.
And there's no consensus as to how a mysterious large ridge that covers more than 75 percent of the moon's equator was formed. It's been a tough nut to crack.
But now a team including an outer solar system specialist from Washington University in St. Louis has proposed a giant impact explains the ridge, up to 20 kilometers tall and 100 kilometers wide.
William B. McKinnon, PhD, Washington University professor of earth and planetary sciences in Arts & Sciences, and his former doctoral student, Andrew Dombard, PhD, associate professor of earth and environmental sciences at the University of Illinois Chicago (UIC), propose that at one time Iapetus itself had a satellite, or moon, created by a giant impact with another big body. Read more here.