This month we have one of the better annual meteor showers, the Orionids. The earliest meteors from this shower will start arriving in a sky near you about October 2 and continue to flash across the sky until about November 7. The shower is predicted to peak on October 21 and as many as 70 meteors have been seen in the past. This year the experts are expecting a more modest 15 to 25 meteors per hour.
When observing a meteor shower, you can trace the meteor trails back to a single area in the sky. This point is called the radiant. The meteor shower is named for where the radiant is situated. The Orionid radiant sits in the Orion constellation near where it borders with the constellations Gemini and Taurus. The Orionids are left over debris from Halley’s Comet and this material is scattered all along its orbital path. The meteors are travelling quite briskly at 66 km/hr and at this high speed, produce a larger number of fireballs than a typical meteor shower.
Unfortunately, this year the Moon will be waning gibbous. It will be about 55% the brightness of a Full Moon. This will obscure seeing some of the fainter meteors. Waning means that the Moon is past full and the term gibbous indicates that it still has a bright crescent shape to its bright area.
Let’s review a few good practices for meteor observing. Dress warmly! A cool autumn evening will suck the heat from your body faster than an eye blink and drive you back indoors. Wear a hat, a warm coat and boots. To minimize the Moon’s brightness, position yourself so that the Moon is at your back. Trees and/or a building help too. Remember that meteors can appear anywhere in the sky. It’s not necessary to be looking in the direction of the radiant. Make yourself comfortable. A blanket or sleeping bag on the ground or a stable lawn chair minimizes distractions.
The great thing about meteor observing is that you don’t need any equipment other than your eyeballs. The meteors travel too fast and leave too large a trail to follow with binoculars or a telescope. It’s just you and the wide open night sky!
Here’s a fun thing to do: use a sheet of paper to represent the night sky. Make a mark to indicate the constellation Orion. Draw a line, short or long, to show size and direction of the meteors you see. At the end of the evening use a ruler to extend all the lines back. Most should end up in Orion. Any lines that don’t meet in Orion are called ‘sporadics’. They are random bits from who knows where. Some are probably from ancient comets that no longer exist.
The Draconids (constellation Draco) is another shower to watch for in late October. They have been quite spectacular in the past but are not expected to be a great show this year with maybe 10 or so meteors per hour expected.
On October 10th the Southern Taurids (constellation Taurus) peak. This is a minor shower and about 5 meteors per hour are predicted. In early November we can expect a good show from the Northern Taurids. There are a few more fine showers in November and December and I will give you a heads up on them in my next column.
We are in the midst of the best time of the year for astronomy. We have cool, clear nights and darkness falls earlier and earlier as the month progresses.
Venus is bright in the southwest evening sky with Saturn sitting above it. Venus will pass south of Saturn on October 30th. Above these 2 in the sky will be Mars in the south. In the east Mercury and Jupiter can be observed in early October about an hour and a half before sunrise.
October 6th: The Moon passes above Saturn about 4 am.
October 10th: Jupiter is just 1 degree south of Mercury.
October 15th: For those of you with telescopes here’s a challenge. Uranus is in opposition and will be at its brightest. Check the internet for a star chart to help find it in the sky. While you’re at it, check out Neptune and Pluto.
October 16th: Full Hunter’s Moon. Be sure to wear your orange vest when you walk the dog. Put a vest on the dog too!
October 21st: Orionid meteor shower peaks.
October 28th: Moon is 1 ½ degrees north of Jupiter.
October 30th: Venus will be 3 degrees south of Saturn in the early morning around 4 am. New Moon
Let me know how your meteor observing has gone and if some of you more experienced readers were able to find Uranus, Neptune or Pluto.
Well, that’s a wrap. Have a good month and keep looking up!
The Beginner’s Observer’s Guide by Leo Enright is available at the Sharbot Lake Pharmacy or by contacting the Royal Astronomical Society of Canada www.rasc.ca/publications, subscriptions for our very own excellent Canadian astronomy magazine, Sky News, are also available from RASC..