In this week’s live Night Vision program we’ll look at meteor showers, from their astronomical causes to practical tips on how to look for them and what to expect. With the approach of the Lyrid meteor shower later this month, and the Eta Aquarid meteor shower in early May, this is a good moment to talk about what these events are and how best to enjoy them.
Between April 16th and 25th, the Earth’s orbit will take us through a field of space debris left behind by Comet Thatcher. When the debris particles meet the upper atmosphere they heat up and evaporate, leaving a brightly glowing trail of hot, ionized air. From the ground, we see these streaking lights as meteors, or as they’re sometimes called, ”shooting stars.”
As this thin debris stream collides with Earth, its meteors all radiate away from a point in the sky because they’re all coming from the same direction. This direction in the sky happens to be near the constellation Lyra, and so these meteors are called the Lyrids. A handful of Lyrids can be seen around a period of a several days, but the shower will peak around the evening of April 21st into the early morning of April 22nd. At its best, this shower is expected to produce around 20 meteors per hour, or about one every three minutes on average. (Note: This does not necessarily mean a steady rate; sometimes there will be long breaks and sometimes several meteors will come around the same time.)
Then, a couple weeks later, we’ll see the Eta Aquarids, and the debris for this shower has come from the famous Comet Halley. This meteor shower will peak on the mornings of May 5th and 6th, and we would expect somewhere between 20-40 meteors per hour, or about one every two minutes on average.
Observing a meteor shower on a clear night makes for a lovely night of stargazing that anyone can enjoy. It is not necessary to identify any constellations, and you won’t need to use any special equipment like telescopes or binoculars. Meteors can appear anywhere in the sky, and they move far too quickly to see with a telescope, so there’s really nothing else to do but just look up.
To get the most of a meteor shower, you’ll just need a clear night sky, preferably far away from extraneous light sources like cities or highways. It’s best if you can a devote long, continuous time period – i.e. more than a half-hour or so – to watching the sky, since you’ll see more meteors and also you’ll get the benefits of letting your eyes reach their best, well… night vision.
A bright Moon can interfere with the view, and unfortunately the Moon will be almost full on the night of April 21st, making the Lyrids a bit harder to see; however, on May 5th we’ll have an almost new Moon phase which should make the Eta Aquarids relatively easy to see.
Meteor showers are especially nice when you have everything you need to stay comfortable for a long time, so if you can, try to round up some chairs, warm clothing, and snacks and make a nice long night of it. And if you can, the best time to look for meteors will be after midnight.
Oh, and if you happen to know anyone who can arrange good weather on these nights, this might be a good time to ask for a favor.
Night Vision: Meteor Showers is presented by Nick Jarvis on Thursday, April 21st, and Saturday, April 23rd, in the Hansen Dome Theater at 6:45pm. Tickets available online or at the Clark Planetarium ticket desk. Free for members and $2 for everyone else.