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
Comets are frozen lumps of rock left over from the formation of the Solar System. There are different kinds of comets; some are regular (called 'periodic'), while others simply flyby never to be seen again. Before astronomy was better understood, for example prior to the 17th Century, the majority of people believed in alchemy, magic and witchcraft. Hardly anything was known scientifically about the actual mechanics of the Solar System. Therefore superstitious people thought comets, appearing haphazardly to disrupt the natural order of the heavens as they saw it, were a sign from the devil heralding evil intent, or at the very least, a bad omen. People who worked out that the Earth was not the centre of the universe with all things revolving around it (geocentricism) kept quiet about their knowledge if they wanted a quiet (or longer) life. Some who persisted in 'heretical' talk of a heliocentric system paid a terrible price. In Protestant England it was not considered heresy to state that the Earth orbited the Sun as it was in Roman Catholic Italy, but it was still a radical belief.
History of Comet Halley
Comet Halley was named after English astronomer Edmond Halley (1656 - 1742), who worked out that well-recorded comets which had passed through the inner Solar System during 1531, 1607 and 1682 shared such similar orbits that he deduced they were the same comet on return visits. He predicted the next time the comet would pass by for human observation and it did indeed return when Halley said it would, some 16 years after his death. The debris trail from Comet Halley gives us an annual celestial fireworks event in October: the Orionids meteor shower. Comet Halley will next return to the inner Solar System in 2061.
We can work out the years of Comet Halley's visits because it is what is known as a periodic comet. We know Comet Halley was visible in 1066 because it appears on the famous Bayeux Tapestry depicting the Battle of Hastings. However, the earliest historical record of Comet Halley was made by Chinese astronomers (who thought comets were celestial ambassadors), in 240 BC: 'During this year a broom star (comet) was seen at the north direction and then at the west direction'. It was also recorded that the Empress Dowager died that summer. Babylonian skywatchers engraved the record of the next appearance of the comet in 164 BC on a cuneiform script tablet which resides in the British Museum. They also noted it in 87 BC.
Some people have connected the revisit of 11 BC with the birth of Jesus Christ, but Biblical scholars think it was too early and therefore not the fabled Christmas Star. However, the comet's return in 1301 gave the Italian artist Giotto di Bondone inspiration for his artistic rendition of the Star of Bethlehem on the famous painting The Adoration of the Magi. Europe's first deep space mission in 1986 was named Giotto after this artist, as it was sent to visit Comet Halley, passing as close as possible to the comet's nucleus on 13 March, 1986.
In the year 684, according to the Nuremberg Chronicle published 809 years later, there were relentless torrential storms, and if that wasn't bad enough, the populace were blighted by plague. A monk named Eadwine from Canterbury must have taken time out from the transcribing he was working on in 1145 because he drew an accurate portrayal of the comet on his Psalms manuscript.
Comet Halley was visible in 1835 and 1910; uncannily coinciding exactly with the birth year and death year of Samuel Clemens (aka Mark Twain). The author predicted his own demise with obvious cosmic connections, although he wasn't the only person with a link to the comet — the Italian astronomer Giovanni Schiaparelli shared exactly the same years of hatch and dispatch.
October 2009 Diary Dates
- The Orionids meteor shower — the duration of the shower is from 02 Oct - 07 Nov so take a look outside on any clear night of this month
- 03: Uranus 6° south of Moon
- 04: Full Moon
- 05: Mars 6° south of Pollux (beta Geminorum)
- 07: Moon will skim the Pleiades
- 08: (before dawn) Mercury 0.3° south of Saturn. Venus will be around 6° above them
- 12: Mars 1.2° north of Moon
- 13: (before dawn) Venus 0.6° south of Saturn
- 16: (before dawn) Venus and Saturn 7° north of Moon
- 18: New Moon
- 20-21: The Orionids meteor shower maximum
- 21: Antares (alpha Scorpii) 1° south of Moon (occultation will be viewable from the UK and most of Europe)
- 27: Jupiter 3° south of Moon
- 30: Uranus 6° south of Moon
- 31: Hallowe'en — 'Trick or Treat' participants will be able to go from house to house lit by an almost-full Moon; it will be approximately 95%, missing 'Blue Moon' status by less than two days!
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.