Researchers suspect that a photo taken by NASA's Cassini spacecraft may show the "birth" of a brand new moon of Saturn, which could also be the last-ever moon of Saturn.
NASA reported that images taken last year show "disturbances at the very edge of Saturn's A ring — the outermost of the planet's large, bright rings," which could signify the gravitational pull of a nearby object. The object, nicknamed Peggy, is only about one-half mile across, which is too small to be seen in photographs.
According to Carl Murray, lead author of a study analyzing the images that was published online in the journal Icarus this week, "We may be looking at the act of birth, where this object is just leaving the rings and heading off to be a moon in its own right." Murray adds that "We have not seen anything like this before."
Researchers are excited by the find because it could offer new insight into how Saturn's other moons (there are 62 of them, not including Peggy) were formed:
The process of its formation and outward movement aids in our understanding of how Saturn's icy moons, including the cloud-wrapped Titan and ocean-holding Enceladus, may have formed in more massive rings long ago.
A new moon's formation could also help scientists understand how the Earth and other planets in the solar system pulled away from the Sun. Peggy is also significant because, according to NASA, it could be Saturn's last moon:
It is possible the process of moon formation in Saturn's rings has ended with Peggy, as Saturn's rings now are, in all likelihood, too depleted to make more moons... "The theory holds that Saturn long ago had a much more massive ring system capable of giving birth to larger moons," Murray said. "As the moons formed near the edge, they depleted the rings and evolved, so the ones that formed earliest are the largest and the farthest out."
Cassini won't get another shot of the object until late next year, which means scientists won't know for sure whether or not Peggy is a moon or just another icy object floating in space for a long time yet.