Peggy is the informal name for a former

moonlet A moonlet, minor moon, minor natural satellite, or minor satellite is a particularly small natural satellite orbiting a planet, dwarf planet, or other minor planet. Up until 1995, moonlets were only hypothetical components of Saturn's F-ring ...

in the outermost part of

Saturn Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant, with an average radius of about 9 times that of Earth. It has an eighth the average density of Earth, but is over 95 tim ...

's Ring A, orbiting away from the planet. The moonlet was discovered by the ''Cassini'' Imaging Team in 2013 and it may likely be exiting Saturn's A Ring. No direct image of Peggy has ever been made. Similar moons to Peggy include Bleriot, Earhart and Santos-Dumont among others.

Etymology

The name of the moonlet comes from the mother-in-law of Carl D. Murray, a professor at the

Queen Mary University of London Queen Mary University of London (QMUL, or informally QM, and formerly Queen Mary and Westfield College) is a public university, public research university in Mile End, East London, England. It is a member institution of the federal University ...

. Murray named it after his mother-in-law because it was her 80th birthday at the time.

Discovery

The moonlet was first discovered in 2013, although its discovery was possible in 2012. ''Cassini'' took 2 images of the edge of Saturn's

A Ring Saturn has the most extensive and complex ring system of any planet in the Solar System. The rings consist of particles in orbit around the planet made almost entirely of water ice, with a trace component of rocky material. Particles range fro ...

, thereby ruling out it being a cosmic ray artifact. There were disturbances at the edges of Saturn's

, with one of these being approximately 20% brighter than its surroundings. There were also protuberances at the edge of the usually smooth A Ring.

Collision

When it was first discovered, no similar object has been discovered in

's main rings. The moonlet was then seen again in 2014 but it was much dimmer than it was in 2013. Carl Murray suggests that there may have been a collision or was gravitationally ejected, though without evidence. In ''Cassini'' observations past 2014, Peggy appears to be broken into two pieces, with the other being named Peggy B.

References

{{Saturn Astronomical objects discovered in 2013 Moons of Saturn Former objects