Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth - Ptolemy
The summer holidays are barely over when the shops are advertising all kinds of ghoulish apparel and disgusting-looking adornments in preparation for Hallowe'en revelry at the end of October. I have written Hallowe'en specials in previous BATS columns, so for now I'll just update you with the latest scary images from the Astronomy Picture of the Day website. There's last year's Hallowe'en Moon — how spooky are those dark swirling bat-shaped clouds? Even the Moon looks menacing! Another new image is the truly weird 'cosmic phantom' which looks just like an asymmetrical dress to me. What does the unusual reflection nebula in Cepheus, known as VdB 152, remind you of?
Meteor showers are the result of the Earth passing through the debris trail left behind from a comet's last orbit. The showers can be timed and some shows are more spectacular than others, depending upon the amount of debris hitting the Earth's atmosphere. The Moon also plays a part in the spectacle; a brightly-lit moon can drown out all but the brightest fireballs, whereas an invisible new moon allows us a few hours of dark-sky viewing. This month's best meteor shower is the Orionids, so named because they appear to originate from the constellation of Orion. The parent comet responsible for the Orionids is perhaps the most famous in history, Halley's Comet. The Orionids occur between 15 - 29 Oct, with the maximum expected around 20/21 Oct. Unfortunately the Moon will be just about full, which will spoil the celestial fireworks party somewhat.
Comet Hartley 2 (103P) covers Cassiopeia, Perseus, Camelopardalis, Auriga and Gemini during October. Watch out for it on any clear night. On 11 Oct it will pass eta Perseii and on the 19th the comet will rendezvous with epsilon Aurigae. If you can locate M38 in Auriga then try that direction on 22 Oct, as the comet will be nearby. Comet Hartley 2 reaches perihelion (gets closest to the Sun) in the constellation Gemini on 28 October. This is also the day that the Moon occults one of Gemini's stars (see Diary Dates below). If I were an astrologer I'd be promoting this date as auspicious but I'm not so I'll leave that to the mystics.
October Diary Dates
- 07: New Moon
- 10: Mars 4° north of Moon
- 21: Orionids meteor shower peak
- 23: Full Moon (the Hunter's Moon or the Blood Moon)
- 28: Moon occults the star Tejat Posterior (mu Geminorium)
- 28: Comet Hartley 2 reaches perihelion
- 31: Happy Hallowe'en!
Chat about your celestial observances at the H2G2 Astronomy Society. Comment on anything in this edition of Babe Among the Stars by starting a new conversation below.