Tonight … October 20, 2014 … is the best time for watching the annual Orionid meteor shower. And an awesome shower it is! For one thing, it stems from debris from the most famous of all comets, Comet Halley. In fact, the object in the picture at the top of this isn’t a meteor. It’s Comet Halley itself at its 1910 visit. The comet last visited Earth in 1986 and will return next in 2061. Debris in the orbit of this comet – the Orionid meteor stream – is now encountering Earth’s atmosphere. The meteors will become visible in their greatest numbers tonight, and especially in the dark hours before dawn tomorrow morning (October 21). At the peak, from a dark site, you might expect to see about 25 meteors per hour.
The meteors – vaporizing bits of comet ice and dust – will look like streaks of light in the night sky. They’re sometimes called shooting stars.
As is standard for most meteor showers, the best time to watch this shower will be between the hours of midnight and dawn – regardless of your time zone.
Fortunately, in 2014, the slim waning crescent moon rising shortly before sunrise is not in the way and will only enhance your enjoyment of the meteor shower if you find yourself out before dawn. Good chance that you’ll see earthshine on the night side of the moon. Also, before dawn, look for Sirius, the sky’s brightest star. And the planet Jupiter is also very bright – brighter than Sirius – and visible high in the sky before dawn.
As Comet Halley moves through space, it leaves debris in its wake that strikes Earth’s atmosphere most fully around October 20-22, every year. The comet is nowhere near, but, around this time every year, Earth is more or less intersecting the comet’s orbit.
If the meteors originate from Comet Halley, why are they called the Orionids? The answer is that meteors in annual showers are named for the point in our sky from which they appear to radiate. The radiant point for the Orionids is in the direction of the constellation Orion the Hunter. Hence the name Orionids.
Even one meteor can be a thrill. Bring along a blanket or lawn chair – after midnight or before dawn – and lie back comfortably while gazing upward. Although a somewhat modest shower, these swift-moving meteors are sometimes bright, occasionally leaving a persistent train – a glowing streak that lingers momentarily after the meteor has gone!
Bottom line: Best night for the Orionid meteor shower in 2014 is October 20, and especially between midnight and dawn on October 21. Expect to see about 25 meteors per hour from a dark site.