Orionid meteors meet the Moon

You may be able to notice, in the hours after the coming midnight, a few meteors whose paths appear to radiate from Orion, betraying that they are members of the Orionid stream.

This does not rank among the major showers of the year. Its ZHR – the zenithal hourly rate, or estimated number likely to be counted in an hour by a single observer with perfect sky conditions and with the radiant overhead – is 20, as compared with, for instance, 100 for the Perseids of August. The number you see in your actual location and conditions could be much less. The Orionid shower cannot boast the status of the giant constellation from which it gets its name, nor of the famous comet in whose orbit its particles travel – Halley’s.

And, this year is unfavorable in that the Moon, not long past full, is up almost all night, its glare likely to drown out all but the brightest meteors.

Here is the scene for an American location as the Orionid radiant rises into view around midnight.

The Orionid radiant is between Orion’s head and the feet of Gemini, the Twins. You can see that not far from it at this time are not only the Moon and the bright planets Jupiter and Mars but the point we mark as “Earth’s direction of travel.” For our planet is meeting this stream of meteors almost head on, which is why we see most of them after midnight.

There is more about the Halley meteors – the stream that produces the Eta Aquarid shower of May and the Orionid shower of October – in our page about them, including a space diagram of their shared orbit.

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