Friday, January 6, 2012

2012 – A Year for Meteor Showers

The year 2012 is a year for meteor showers, and I don’t mean in relation to the apocalyptic end-of-the-world scenario as some may believe. This year is a year for meteor showers because the new moon coincides with most of the major meteor showers. This means that you can see more of the meteor shower because the light from the moon does not interfere with the fainter meteors that streak by the Earth’s atmosphere. It is simply a case of brighter light dimming the fainter lights. The new moon is always the best time for observing if you wish to see fainter targets – provided of course that you are away from light pollution (bright city/house lights) and that the weather cooperates.

There are 7 major meteor showers and four of them have their peaks during the new moon. They are the Lyrids (April 22), Orionids (Oct 20), Leonids (Nov 13), and the Geminids (Dec 13). This year will be the best time for observing meteors since the next two years will only have one meteor shower during the new moon (Perseids – 12 Aug 2013; & Quadrantids - 3 Jan 2014).

The Lyrids meteor shower has a zenithal hourly rate (ZHR) during the peak of 20 meteors per hour. Its radiant (apparent source or point of origin in the sky) lies a few degrees from Vega in the constellation Lyra. The source of this meteor stream is the comet Thatcher.

The Orionids meteor shower has a ZHR during the peak of 25 per hour. The radiant appears to be along the right arm of Orion the hunter. The source of the meteors is the comet 1P/Halley.

The Leonids meteor shower has a ZHR during the peak of 20 per hour but usually varies and becomes a meteor storm that can generate up to 1,000 meteors per hour. In November 1966 the ZHR was approximately 100,000 per hour. The varying rate suggests that the meteor orbit is fairly young. Its radiant lies inside the asterism of the sickle in the constellation of Leo. The stream originates from the comet 55P/Tempel-Tuttle. The meteors move across the atmosphere with speed of 44 miles per second and as a result would generate more fireballs (very bright meteors) from large amounts of friction with the atmosphere.

The Geminids meteor shower, a personal favorite, has a ZHR during the peak of 120 per hour (approx 2/min). Although the slowest of the meteor showers, the Geminids still produce fireballs as a result of their denser and heavier meteors. The radiant of the meteor is close to Castor of the constellation Gemini. The stream originates from the asteroid 3200 Phaethon.

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