AstroTalk Episode April 27, 2017
Earhart Propellor in Saturn`s A Ring
3:16pm - 3:25pm
on March 22, 2017, NASA`s Cassini Spacecraft took close up pictures of something called an Èarhart Propellor``, in Saturn`s A Ring. This is the second time NASA has targeted an individula propellor in a ring in Saturn. The first such propellor tarteted was the Santos-Dumont (PIA21433) propellor, one month earlier. Moonlets are sometimes thought to form in Saturn`s rings, and when they do, objects called ``Porpellors`form as well. Prpellors are disturbances in a ring, that are caused by the formation, or presence, of a moonlet. Earhart is brighter than Santos-Dumont, and the third propellor which will be flimed in the near future,"Bleriot," will be imaged in April 2017. Earhart is close the Encke Gap, which is 200 miles wide. The Encke gap is thought to be held open by the moon Pan. Pan is 100os of times more massive than Earhart, so it can open up a gap that extends all the way around the ring it inhabits. The mass of the ring itself closes off the gap made by Earhart, before the gap can extend too far. Wave features are also seen to the left of Earhart. These are caused by the moons, Promehteus, Pandora and Pan.