Halley’s Comet won’t make another appearance in Earth’s skies until 2061, but until then, we can enjoy the annual Orionids meteor shower made by dust from the comet’s wake. The dazzling display lasts from early October until November 7, and peaks between 1 a.m. and dawn on Wednesday, October 21, Joe Rao reports for Space.com.
Comets leave a trail of debris as they soar through the solar system, and as Earth orbits the Sun, it collides with these collections of cosmic litter. Bits of material, some as small as grains of sand, fall into Earth’s atmosphere and burn up, creating a streak of light that looks to us like shooting stars. The Orionids meteor shower isn’t the brightest of the year, but its meteors are unusually speedy and it’s one of only a few meteor showers that’s equally enjoyable in both the Northern and Southern hemispheres.
Other meteor showers, like the Perseids in August and the Geminids in December, are reliable showstoppers. But about half of Orionids’ meteors leave behind persistent trails, or bright streaks of light made by ionized gasses that stick around for a few seconds after the meteor is gone, Deborah Byrd writes for EarthSky.
At the Orionids peak, about 10 to 20 meteors shoot by per hour, Nicholas St. Fleur reports for the New York Times. And this year could offer a particularly good chance for spotting each streak of light. The new moon, when the dark side of the moon faces Earth, was on October 17, so on the morning of October 21, the moon will be a thin, waxing crescent and will set in the evening. Without moonlight interfering, even quick, faint meteor trails should be visible.
Light from buildings, cars or streetlamps do affect the visibility of the meteor shower, though. So to watch the Orionids, the first step is to find an area without light pollution, away from towns or city lights. There’s no need to bring binoculars or a telescope to watch meteor showers, since they limit the amount of sky you can see at once. (There's plenty to see in the night sky with binoculars, so they might help to pass the time.)
To watch the show, “lie flat on your back with your feet facing southeast if you are in the Northern Hemisphere or northeast if you are in the Southern Hemisphere, and look up, taking in as much of the sky as possible,” NASA recommends.
After about 30 minutes, your eyes will adjust to the low light and give you the best view of a starry sky. (You can use red light lamps to move around safely without affecting your night vision.)
The meteor shower is named for the Orion constellation because that’s where the meteors seem to emerge from. The constellation, recognizable by the mythical hunter’s three-star belt, will be near the eastern horizon. The meteor shower will emerge about 30 degrees above the constellation’s second-brightest star, Betelgeuse, per Space.com. To measure 30 degrees, you can use your fists—held at arm’s length, the height of your fist is equal to about ten degrees of night sky. Just count three fist-lengths above Betelgeuse and settle in for the show.