My earlier article on the Perseid Meteor shower back in August, seemed to help lots of people. So I’m going to follow the same format here for the next big shower, the Orionids.
Q. What are the Orionid meteors?
A. Each year in October as the Earth orbits about the Sun, it passes through an area of Space containing dust and rock fragments left behind by Halley’s comet. As these particles hit the Earth’s atmosphere they burn up, producing streaks of light we can see in the Night Sky. Occasionally, larger particles may burn up producing very bright “Fireballs” that can sometimes even be seen in daylight
Q. Why is this October meteor shower called the “Orionids”?
A. Because of the location of the Halley’s Comet debris in space, the meteors APPEAR to us on the Earth’s surface to originate from the constellation of Orion. This is nothing more than a “line of sight” effect however. The rock fragments which cause the meteors are actually very close to Earth – they have nothing to do with the distant star pattern we call Orion.
Here’s a graphic showing the apparent origin of Orionid meteor trails (the Radiant), located between the constellations of Orion and Gemini.
Q. So will the meteors be seen only in the area of Orion?
A. No. The streaks of light may appear anywhere in our sky… But if you extend the traces backwards and continue the path, they will seem to have started in the area of Orion.
Q. When is the best time to look for the Orionid meteors?
A. The range of dates is expected as 16th – 27th October, with the peak meteor activity expected on 21st October 2009. In recent years, good numbers of meteors have been seen 1-2 days before and after the peak date, so it should be well worth observing over the period 18th-23rd October.
In some previous years, a double-peak of activity has been reported and this is an unusual feature of the Orionid shower. This may be because the orbit of Halley’s Comet brings it back to the Sun every 76 years, giving plenty of opportunity for depositing dust and debris.
Q. Will 2009 be a good year to observe the Orionid meteors?
A. It should be. Sometimes a bright Moon spoils the observing of meteor showers, but this time it’s very favorable. At the expected Orionid peak, the Moon will be just 2 days old. Therefore, it won’t be bright and it will set below the horizon, soon after sunset.
Q. How many meteors can I expect to see?
A. At the shower peak, something like 25 meteors per hour is predicted (this is called the ZHR – Zenithal Hourly Rate). Obviously, you will need dark, clear sky conditions to see the most meteors, and the number is just a prediction.. this makes it more fun to get outside and see for yourself, how many meteors appear!
Q. What equipment do I need to observe the meteors?
A. Good news… no equipment is really needed – just use your eyes (it will help if you allow 10-15 minutes for your eyes to become accustomed to the dark). If you like, you can try using binoculars too, but they may limit your view to a small area of the sky.
Q. Any other suggestions?
A. It’s getting cold in October, so make sure you wear warm clothing if you’re planning to spend an extended period outside, watching for meteors. Your observing session will also be more comfortable with a reclining garden chair, allowing you to lay back and look upwards. Some people like to put blankets or cushions on the ground, so they can lay flat and feel closer to the Universe, as they hopefully experience a memorable meteor display in the Night Sky.
Here’s wishing you the best of luck with your Orionids 2009 experience!
If you have questions or comments, please leave a reply below. I’ll do my best to answer each one personally (although I have to admit, the hundreds of questions on the Perseid meteor post, rather overwhelmed me!).