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
This month there's a real treat in store for comet hunters - Comet ISON becomes visible and there's a second one to track down, in the same region of the sky. Comet Encke is rather a bridesmaid; it was the second historical comet to be pronounced 'periodic' (which means its course and behaviour are predictable). The first periodic comet was, of course, undoubtedly the most famous one, Halley's Comet. Comet Encke is named after the German astronomer Johann Encke who calculated its orbit and correctly predicted its next appearance in 1822. The appearance of Comet Encke this month is predicted to be on a par with its fellow Comet ISON, brightening from 11th to 7th magnitude. Comet Encke will be a pre-dawn object, commencing the month in Gemini, the Twins; it will pass above Castor and Pollux between 5-7 October. Comet Encke will traverse the sky faster than Comet ISON because it is nearer to the Earth. Comet ISON is closer to the planet Mars during October, and thanks to the Moon we'll only have the first half of the month to try and catch a glimpse of its tails. Then we will have November's spectacular showtime to look forward to!
Cross-quarter days occur halfway between an equinox (equal day/night) and a solstice (minimum day/maximum night in the Northern Hemisphere). One such cross-quarter day is Hallowe'en, 31 October, when denizens of planet Earth like to dress up and party, or take their children trick-or-treating. There are ghostly images in space, along with witchy nebulae, spectral supernova remnants and cosmic phantoms!
Wave at Saturn update
Do you remember I asked you to wave at Saturn on 19 July? Here are some connected photos - see if you can spot yourself!
October Diary Dates
- 01 (pre-dawn): look east before sunrise for Comet ISON, just 2° north of Mars
- 01: The Moon passes 7° south of Mars
- 05: New Moon
- 06: The Moon passes 3° north of Mercury
- 07: The Moon will be less than 2° south of Saturn
- 7/8: Draconids meteor shower peak
- 08: The Moon passes 5° north of Venus
- 10: Mercury passes 5° south of Saturn
- 15 (pre-dawn): Comet ISON, Mars and Regulus form a straight line
- 15: The Moon passes 6° north of Neptune
- 16: Venus passes 1.6° north of Antares (alpha Scorpii)
- 17: The Moon passes 3° north of Uranus
- 18/19: Penumbral lunar eclipse visible from Europe, the Americas, Africa and Asia
- 19: Full Moon (the Hunter's or Blood Moon)
- 20/21: Orionids meteor shower peak
- 25 (pre-dawn): Comet ISON is 1.7° south of M95, a barred spiral galaxy in Leo
- 25: The Moon passes 5° south of Jupiter
- 29: The Moon passes 6° south of Mars
- 31: Cross-quarter day Hallowe'en
- 31: Comet ISON crosses Earth's orbit1
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.