Vega marks radiant point of April’s Lyrid Meteor Shower

The 2012 Lyrid meteor shower is now picking up steam under the darkness of the new moon. A dark sky is best for meteor showers, and in 2012, there is no moonlight to spoil the show. What’s more, the 2012 Lyrid shower should be at its best during the weekend, in the wee hours before dawn.

Find out more about the Lyrids here

Plus …
2012 Lyrid meteors best before dawn April 21 and 22
2012 Lyrid meteor shower and Lyra the Harp

This shower will probably rain down the most meteors in the dark hours before dawn on Sunday, April 22. However, meteor showers have an element of unpredictability to them, so you might want to watch between midnight and dawn on Saturday, April 21, as well. On any clear night this weekend, the Lyrids start off at late evening, but the meteor numbers tend to pick up after midnight and to be the greatest in the dark hour before dawn. Give the shower a try. It’s generally a fairly modest shower, perhaps offering 10 to 15 meteors per hour.

If you trace the paths of these meteors backward on the sky’s dome, you’ll find that they appear to originate from a point in the sky near the the star Vega, the heavens’ 5th brightest star. This is the shower’s radiant point. The radiant point for the Lyrid shower sits just to the right of Vega, which is the brightest star in the constellation Lyra the Harp. It’s from Vega’s constellation Lyra that the Lyrid meteor shower takes its name.

You don’t need to identify Vega in order to watch the Lyrid meteor shower. The idea that you must recognize a meteor shower’s radiant point in order to see any meteors is completely false. Any meteors visible in a moonless sky will appear unexpectedly, in any and all parts of the sky.

Why between midnight and dawn? It’s because that’s when the star Vega – and the shower’s radiant point – is above your horizon. Vega rises above your local horizon – in the northeast – around 9 to 10 p.m. It climbs upward through the night. The higher Vega climbs into the sky, the more meteors that you are likely to see. By midnight, Vega is high enough in the sky that meteors radiating from her direction streak across your sky. Just before dawn, Vega and the radiant point shine high overhead. That’s one reason the meteors will be numerous then.

So why near Vega? Why do the meteors radiate from this part of the sky? The radiant point of a meteor shower marks the direction in space – as viewed from Earth – where Earth’s orbit intersects the orbit of a comet. In the case of the Lyrids, the comet is Comet Thatcher. This comet is considered the “parent” of the Lyrid meteors. Like all comets, it is a fragile icy body that litters its orbit with debris. When the bits of debris enter Earth’s atmosphere, they spread out a bit before they grow hot enough (due to friction with the air) to be seen. So meteors in annual showers are typically seen over a wide area centered on the radiant, but not precisely at the radiant.

How high up are meteors when they begin to glow?

Could Earth collide with a comet that causes a meteor shower?

In a good year, you’ll see perhaps 15 meteors per hour in a dark, moonless sky. That’s in contrast to the year’s best showers – the Perseids of August and Geminids of December – both of which typically produce about 60 meteors per hour.

Still, the April Lyrids can surprise you. They’re known to have outburts of several times the usual number – perhaps up to 60 an hour or so – on rare occasions. Meteor outburts are not predictable. So – like a fisherman – you must take your lawn chair, a thermos of something to drink, whatever other gear you feel you need – and wait. You’ll be reclining outside in a dark location, breathing in the night air and gazing up at the starry heavens. Not a bad gig.

Just remember .. the new moon makes 2012 a favorable year for Lyrid meteor shower. Lie down on a reclining lawn chair in a dark spot away from pesky city lights, enjoying the brilliant star Vega and the Lyrid meteor shower!

Find out about meteor showers for the rest of the year: EarthSky’s meteor shower guide for 2012

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