Halley’s Comet won’t be visible for 39 more years, but at least we can enjoy its dust. The annual Orionid meteor shower, a byproduct of Halley’s most recent pass near Earth, has begun.
The shower is set to last for the rest of October and the beginning of November. But it will reach its peak for skywatchers in the U.S. Oct. 21 through Oct. 22. The new moon is on the 25th—meaning skies will be extra dark for the best part of the space spectacle.
In the past, the Orionids have produced up to 80 meteors an hour, but in more recent years’ displays have peaked around 20-30 visible “shooting stars,” which is about what we can expect this month according to Space.com. Yet still, the shower is likely to put on an exciting show, as the Orionids intersect with Earth’s orbit head-on, making the meteors speedy and rather dramatic, according to NASA. The shower is known to sometimes produce fireballs, i.e. extra-bright meteors.
Like all visible meteor showers, the Orionids are a phenomenon of particles intersecting with (and burning up in) Earth’s upper atmosphere. And Orionids’ particles come from the meteor stream of one of the most well-known comets: Halley’s.
Also known as 1P/Halley, Halley’s Comet has an elliptical orbit around the sun which brings the mass of rock and ice close to Earth about every 76 years. As the comet warms up in the heat of our inner solar system, bits of ice and other debris fall off and end up suspended at the intersection of our orbit and Halley’s.
So, each fall, Earth is treated to a meteor shower from the remains of a comet long past. Halley’s frisbee-shaped path intersects Earth’s orbit twice on each go-around, meaning there’s another corresponding visible meteor shower called Eta Aquariids, which happens around May.
Though named after Orion because the meteors appear to spawn from a radiant point near the constellation, the Orionids will be visible across much of the sky. In fact, the meteors with the most impressive trails will likely appear farther from Orion, according to Space.com.
Note: Orion isn’t actually producing meteors at all, the constellation is much farther away from earth than the shooting stars are. Instead, the radiant point is a trick of perspective.
For starters, check the forecast and aim for a cloudless night. Remember, closer to the new moon and the Oct. 21-22 peak is better. Then, head somewhere dark—as far away from city lights as possible—and wait for your eyes to adjust. It’s best to post up in the wee hours of the morning, as the radiant point will be at its highest around 2 a.m.
In the northern hemisphere, Orion is in the southwest quadrant of the fall sky and in the southern hemisphere, it’s in the northwest.
For optimal meteor spotting, position yourself to get as broad a view of the sky as possible. Laying down flat on your back is usually best (bring a blanket and/or a sleeping bag). It’s worth scanning the whole sky, but the most spectacular meteors are likely to appear about 45 to 90 degrees away from Orion, according to NASA.