October 28 – Asteroid 33 Polyhymnia

The Greek muse of sacred music was chosen to be the namesake of French astronomer Jean Chacornac’s second asteroid, 33 Polyhymnia, discovered on October 28, 1854.
Approximately 62km in diameter at its widest point, and rotating once every eighteen hours, this S-type main belt minor planet has an absolute magnitude of 8.55, and an unusually high eccentricity for such an early discovery, which helps it to reach quite good apparent magnitudes at certain times (10th magnitude is not unknown when Polyhymnia is close to Earth).



The muse Polyhymnia is often depicted as rather a serious figure, in a thoughtful or contemplative pose (holding her finger to her mouth, for example). Now, this is all very well for the muse of sacred hymns, but as she is also responsible for pantomime, I’m not sure I can take her all that seriously.

1971   ⇒    Launch of the Prospero satellite (X-3) by the UK, using a British Black Arrow rocket, making it the first all-British launch (almost – the launch took place from Woomera, South Australia).  The UK’s previous satellite was called Ariel, so you’ll probably not need telling which Elizabethan playwright is being nodded toward in the choice of names.  Prospero is still up there, and isn’t expected to decay until 2070.

A "spare" Prospero, on display in the Science Museum, London. (Image credit: Geni).

A “spare” Prospero, on display in the Science Museum, London. (Image credit: Geni).

Although no longer a working satellite, Prospero has been contacted every few years, usually on the anniversary of its launch (but less often recently).



April 06 – 25 Phocaea

Two asteroids to start us off today, discovered by the same guy on the same day, two years apart.  I like people who stick to a routine.

1853  –  Asteroid 25 Phocaea was discovered by Jean Chacornac.  Phocaea is the Greek version of the Turkish town Foça, home of the Turkish Navy’s equivalent of the SAS.

1855  –  Asteroid 34 Circe discovered, also by Jean Chacornac.  Circe is a more typical asteroid name than Phocaea, coming as it does from Greek mythology.  Circe is a minor goddess, known for killing her husband and being banished to the island of Aeaea, the land that consonants forgot.

Odysseus chasing Circe. (Image: Marie-Lan Nguyen)

Odysseus chasing Circe. (Image: Marie-Lan Nguyen)

Chacornac discovered six asteroids and a comet, which was enough to eventually get him his own asteroid (1622 Chacornac), and I suspect that his theory of crater formation may have had a bearing on a crater on the Moon being named after him.  It’s just southeast of Posidonius.

1878  –  Asteroid 186 Celuta was discovered jointly by Paul and Prosper Henry (this one is credited to Prosper), and named for a fictional character in works by the French writer Chateaubriand.  It is an S-type asteroid of approximately 50 km in diameter.

1891  –  Main belt asteroid 309 Fraternitas discovered by Johann Palisa.

1965  –  Communications satellite Intelsat 1 (“Early Bird“), built by the Hughes Aircraft Corporation, was launched from Cape Canaveral.