Monday, December 03, 2007


We're getting some wonderfully crisp, clear winter nights now.
You know, its definitely worth getting up early and having a look around the night sky at present.
At 6am, (although its all visible until virtually 7am at present), Venus is still gloriously bright in the south east (along with the crescent moon at the moment), Mars is still very bright indeed, due west, slap bang next door to the star Mebsuta in the constellation Gemini (the Twins).

Move your eyes in the direction of 11 o'clock from the bright orange planet Mars, and you'll suddenly realise you are looking at the famous twins themselves, Castor and Pollux, or to give them their Greek names, Kastor ("He who excels") and Poludeukeis ("Very sweet").

The left hand star (as you look at it) is actually Pollux, which appears orange to the naked eye. Castor, to the right, appears blue, though in actual fact, through a decent telescope, Castor is revealed to be quite an incredible multiple star, comprising of six separate components.

As with virtually all these myths and legends, accounts of Castor and Pollux do vary considerably, especially between ancient Greece and Rome.
A popular version is that these twins were the brothers of Helen of Troy, members of Jason's Argonaut crew (its bound to be on tv over christmas again - great!), and of mixed parentage - both having Leda as their mother, but Castor's father was King Tyndareus of Sparta (Castor was mortal originally) whereas Pollux's father was the God of Gods, Zeus himself, (Pollux was always immortal).
Zeus wooed Leda (and Pollux was the immortal result) in the guise of a Swan, Cygnus, (another constellation in the night sky) - every night sky tells a story!

The twins, since ancient times, have always been used as a very good measurement of angular distances, being exactly 4.5 degrees apart.
They are two of the patron saints of mariners, appearing in ships' rigging as the electrical phenomenon "St. Elmo's Fire" (remember the 1985 film of the same name (metaphorically related I suppose) and John Parr's number one hit? Ok. Just me then).

Remember the twins, especially in December. Between the dates of the 7th and 15th December (approximately) and peaking between the 12th and the 14th, the very consistent Geminids meteor shower will be visible in the night sky, if we are lucky enough to have clear viewing conditions.

The Geminids are caused by an object named 3200 phaethon, which is thought to be an extinct comet.
The meteors in this shower appear to come from a radiant , (a point in the sky), near Castor, in Gemini, (hence the shower's name). However, they can appear almost anywhere in the night sky, and often appear yellowish in colour.
The meteors travel at medium speed in relation to other showers, at about 20 miles per second, making them a little less "blink and you'll miss 'em" than other "shooting stars"!

As I said, do have a look at Venus, Mars and Castor and Pollux in the night sky at present, and lets hope for clear skies in middle of the month...


nicola said...

bit of useless information:

"un castor" in french means beaver

"pollux" is the name that the french give to Dylan in the Magic Roundabout.

As the Americans would say: "go figure".

The Black Rabbit said...

Beaver and Dylan then.
Easy to remember...

electrichalibut said...

And castor oil is so named because it's a substitute for another product (with a similar explosive purgative effect) called castoreum which was extracted from the perineal glands of beavers. True story.

The Black Rabbit said...

And allllll because the latin name for the beaver family is CASTORIDAE

Annnnd relax.