May 18 – Discovery of Uranus’ Moon, Perdita.

This discovery was slightly unusual, as the photograph used to discover Perdita was taken in 1986 by Voyager 2, but the tiny moon wasn’t noticed until 1999, which therefore goes down as the year of discovery.  Following this, it wasn’t possible to verify Perdita’s existence, so it was stripped of the title “moon” by the International Astronomical Union until the Hubble telescope picked it up in 2003.

The name Perdita is an inspired choice.  All the moons of Uranus are named after characters from the plays of William Shakespeare or The Rape of the Lock by Alexander Pope.  Perdita, daughter of Laontes in The Winter’s Tale, has a name meaning “lost”.  She grows up believing she is a poor shepherd’s daughter, only to find out later that she is a princess.

Engraving of Florizel, Prince of Bohemia, and Perdita, by Charles Robert Leslie.

Despite being just 33km wide, Perdita is by no means the smallest of Uranus’ moons.  Indeed she is quite large compared to some of the most recent discoveries.  Mab, for example, is only 25km in diameter, Fransisco 22km, and Trinculo and Cupid both a teeny 18km.


ALSO TODAY . . .

1895  —  Asteroid 403 Cyane discovered.

1912  —  Asteroid 758 Mancunia discovered.

1969  —  Apollo 10 launched.

1991  —  Helen Sharman becomes the first Briton in space.

2006  —  Exoplanets HD 69830 b, c, and d discovered,