After thirteen years of some truly epic space exploration, NASA’s Cassini spacecraft ended its career by exploding on the atmosphere of Saturn in a controlled collision. Cassini was responsible for making some of the most groundbreaking discoveries in our solar system including detecting possible life-sustaining conditions on Saturn’s moon Enceladus. Cassini gave us an unprecedented look at Saturn and her moons, giving us a glimpse at what true alien worlds are like.
Even in its final moments, Cassini continued to make some startling discoveries. As it approached its final resting place in Saturn’s upper atmosphere, Cassini snapped some photographs of one of Saturn’s most mysterious features, named “Peggy” after the mother-in-law of the scientist who discovered it.
Peggy has been described as an odd “glitch” in one of Saturn’s outermost rings. Through a telescope, Peggy appears to be an anomalous bright spot in Saturn’s rings, but up close appears a lot stranger. Saturn’s rings are typically smooth-looking and perfectly circular owing to the planet’s gravity, but Peggy looks like a strange rough or jagged area and measures some 750 miles across.
Carl Murray of Queen Mary University of London worked on the Cassini project for nearly three decades and was responsible for naming Peggy. Murray was among the first to discover Peggy and says even after all these years, NASA scientists still don’t know what the ‘glitch’ might be:
We obviously wanted to know, ‘Was it real? What is it? Where did it come from? Where is it going?’ We’ve been tracking it almost ever since. We’ve never actually resolved the object. All we can do is track the glitch.
Main theories for what Peggy might be include a dense cloud of dust and debris caught in Saturn’s gravity, or even perhaps a tiny proto moon that hasn’t quite broken free of the planet’s pull yet. For now, Peggy will remains a mystery until the next deep-space probe can get a good look at her.