In the early hours of Wednesday, October 21, 2020, planet Earth will plunge through a trail of dust and debris left in the in the inner Solar System by the most famous comet of them all.
Did you see Halley’s Comet when it was last in the Solar System in 1986? Also known as 1P/Halley, it’s next due back in our neighborhood in 40 years.
It’s reckoned to be the only naked-eye comet that can appear twice in a human lifetime. Unlike Comet NEOWISE, which isn’t coming back for 7,000 years.
It’s also responsible for two annual meteor showers, one of which peaks this coming week—the Orionid meteor shower.
Here’s everything you need to know about when to look, where to look and what you’ll see if you go outside looking for shooting stars this week.
What is the Orionid meteor shower?
It’s an annual meteor shower of medium strength that occurs between October 2 and November 7 in 2020. Expect between 10-20 “shooting stars” on the peak night, which travel at 41 miles/67km per second. That’s very fast. though Orionids do tend to have long, visible trains—streaks in the sky that are visible for a second or so.
When is the Orionid meteor shower?
The peak—when most activity is expected—will take place in the early hours of Wednesday, October 21, 2020. At that point the young Moon will be 23% illuminated, so just a crescent, thus shouldn’t be much of a problem at. The key time to watch is the few hours before dawn according to EarthSky.
You can, of course, take your chances and look well before midnight—and you may well spot some shooting stars—but the major activity will take place when skies are darkest.
Why is it called the Orionid meteor shower?
Although they are caused by Halley’s Comet, the Orionids get their name from their apparent point of origin—their radiant point. That’s within the constellation of Orion, which is rising in the east around midnight.
More specifically, it’s close to Betelgeuse, but the “shooting stars” can appear anywhere in the night sky.
Where is Halley’s Comet now?
You won’t see Halley’s Comet until the year 2061 so don’t bother looking—it’s way, way, way too dim—but know that its current position is within the constellation of Hydra, the water snake. It’s a tricky constellation to make out in its entirety, but if you’re looking at the constellation of Orion as you wait for shooting stars, cast your eyes due east and Hydra will be rising.
So while Halley’s Comet isn’t close at all to us at present—in fact, it’s outside the orbit of Neptune—it’s lurking out there in the same field of view as the radiant point of the Orionids.
Who was Edmond Halley?
An English astronomer born in 1656, Edmond Halley used Isaac Newton’s theories of gravity and planetary motion to calculate the orbits of comets. He predicted that comets don’t just make one journey through the Solar System, but can make many return trips.
Based on reports of a bright comet being visible in the night sky in 1532, 1607 and 1682 he predicted that it was the same comet, and that it would return to the inner Solar System in 1758.
He was dead right, and in more ways than one—he died in 1742 before seeing his work come to fruition.
What other meteor shower does Halley’s Comet cause?
The debris stream from Halley’s Comet causes the Orionids meteor shower but it also causes the Eta Aquarids meteor shower in May. That’s because it deposits meteoroids in the orbital path of the Earth both on its way in, and on its way out, of the Solar System. Earth intersects Halley’s Comet’s path around the Sun twice every year.
The Eta Aquarids meteor shower—known for fast-moving meteors and numbering around 10-20 per hour at its peak—will take place between April 19 and May 28, 2021, and peak on the night of May 5, 2021.
When is the next meteor shower?
The next major meteor shower is the Leonids, which will peak in the very early hours of November 17, 2020 in dark, moonless skies. Expect about 15 fast-moving “shooting stars” per hour for the Leonids meteor shower in 2020.
However, the one to get prepared for is the Geminid meteor shower, the year’s very best, which will peak early on December 14, 2020 and unleash as many as 120 “shooting stars” per hour—and just a few hours before a precious total solar eclipse.
Wishing you clear skies and wide eyes.