The Orionid meteor shower — one of the year's most spectacular natural light shows — is upon us. This weekend, Earth will plow through a dense stream of celestial debris given off by Halley's Comet. These fragments of Halley will collide with the planet's atmosphere at speeds approaching 150,000 miles per hour, setting the night ablaze as they streak and explode across the pre-dawn skies of Saturday, October 20th and Sunday, October 21st.
Astronomers are predicting that Sunday's shower, in particular, will be one of the most impressive of 2012. Here's everything you need to know to spot as many meteors as possible.
Up top: The 2011 Orionid Meteor Shower at its peak, photographed by astrophotographer Brad Goldpaint near Mount Shasta, CA. See the full image below.
Mike Brown (the astronomer who killed Pluto) likes to say that the Moon is his nemesis, because it washes out his view of celestial bodies in the night sky. And while you may not agree with Pluto's demotion, you'd be wise to take Brown's dictum to heart; when you're looking for meteors, the Moon is your enemy.
Fortunately, the Moon isn't expected to be much of an issue at all this weekend. Not only will it be a waxing crescent (just five days past-new), it will also be entirely absent from the pre-dawn sky. No Moon, of course, means no moonlight to wash out the gleam of meteors streaking overhead.
But city lights, street lights, house lights, flashlights, any lights can be just as bad. Your surroundings will be giving off tons of the stuff, as will your personal items — so don't blow your vision by checking your indiglo watch out of habit and for god's sake don't look at your phone.
If you're in the country, go find a big open field. If you're in the city, get out if you can. If you can't get out, try to find a high point.
Taking all these things into account can make a huge difference. The images featured here help illustrate the effect that light pollution can have on your stargazing experience. The bottom photo was taken in Orem, Utah — a major metropolitan area with around 400,000 people. The top photo was taken in Leamington, a rural Utah town, about 75 miles southwest of Orem, with a population of just 217 people. The difference in visibility is staggering. Give it a little forethought, and you can vastly improve your experience; the Clear Sky Chart website has a great list of optimal viewing locations organized by state, so go check it out.
Once you're all settled in at your prime viewing spot, give your eyes at least 20 minutes to fully adapt to the dark. How do you know if your eyes have adapted? A good rule of thumb says if you can see all the stars in the little dipper (you should count 10) you'll see plenty of meteors. If you can't spot all 10 it's not a big deal, that's just under optimal conditions.
The best hours for catching the Orionids will be between midnight and dawn on the mornings of October 20th and 21st. If you can only be awake for one morning, make it the 21st — that's when activity is expected to peak.
You can also use NASA's Fluxtimator to help calculate the ideal time to direct your gaze skyward. The Fluxtimator even takes your viewing location (i.e. whether you're observing from the city or the countryside) and the brightness of the Moon into account — just be sure to adjust date and location information accordingly.
As for where to look, that depends on who you ask. Some people will tell you to look towards the radiant, where the shooting stars will appear to emanate from (for the Orionids this is near the constellation Orion):
Bear in mind, however, that meteors' trails tend to be shorter the closer they are to the radiant. Your best bet is to probably just look straight up keeping in mind that meteors can appear anywhere in the sky.
If you'd like to join local experts, click here to find your neighborhood astronomy club, and find out whether they'll be setting up a telescope you can peek through with friends. And if there's no local club, you can alwaysjoin NASA's live, online chat about the shower.
Bring a reclining lawn chair, a blanket, some pillows and a coat, as it's likely to get chilly. Basically, bring whatever you need to get comfortable and still keep your eyes on the sky. Don't try to stand. Standing and looking up may seem like a decent enough idea, but eventually your neck will get tired, and the second you take your eyes off the sky is invariably when the brightest meteors of the night will go blazing by — it's like a code that all meteors live by.
You shouldn't really need a telescope or binoculars, because you'll want to keep your eyes on as much of the night sky as possible. Bring something to snack on, but nothing you have to look at to eat. Hot chocolate is always nice. And finally, bring some good company, so you have somebody to "ooh" and "ahh" with while stargazing on this beautiful autumn night.