Stargazers anticipated a dazzling light show to erupt across the night sky just before midnight on November 21, 2019.
Scientists predicted that the Alpha Monocerotid meteor shower, also known as the “unicorn meteor storm,” would display as many as 400 “shooting stars” during its peak. The peak was estimated to begin at 11:45 p.m. ET and last between 15 minutes and 45 minutes.
UPDATE: The American Meteor Society reported that a more low-key shower occurred just before midnight. In the video embedded below, you can see a few meteors beginning at about the 4:12:00 mark. The Society said that about a dozen meteors over the course of about 30 minutes. Several other live streams were canceled due to cloudy skies.
Here’s what you need to know.
1. The Meteor Storm Gets the ‘Unicorn’ Name Because Of the Constellation Where It Appears to Originate
This astronomical event is referred to as the “unicorn meteor storm.” It gets the name because the show appears to stem from the constellation Monoceros, which is the Greek word for unicorn.
The constellation was among those listed by the Greek astronomer Ptolemy during the second century, according to the Farmers’ Almanac. Monoceros is typically tough to spot with the naked eye because of its 32 stars, only two shine brightly enough to see.
2. The Last Major Meteor Outburst From the Unicorn Happened In 1995
Scientists Peter Jenniskens and Esko Lyytinen are the two experts who predicted that the Alpha Monocerotid meteor storm could be a dazzling display on November 21. This particular meteor shower actually occurs annually as the Earth passes by the debris field. But there are typically too few meteors to capture much attention.
According to the American Meteor Society, the unicorn meteor storm has had four known major outbursts: 1925, 1935, 1985, and 1995. The one that occurred in 1995 was anticipated and astronomers were able to capture images of the show. The bright show occurs when the dust from the comet travels closer to Earth.
Jenniskens and Lyytinen are predicting that tonight’s storm will be similar to one that happened in 1995. During that event, about 400 meteors were visible at a rate of about 5 or 6 meteors per minute.
Jenniskens is a senior research scientist at NASA’s Ames Research Center. Lyytinen works with the Finnish Fireball Network.
3. The Comet That Prompts This Rare Meteor Storm Is Shrouded In Mystery
The unicorn meteor storm is fascinating in part due to the mystery surrounding it. Astronomers know that the Earth passes through a field of debris left behind by a comet. That’s where the meteors come from.
But scientists don’t know anything about the comet’s origins or when it may have passed by this spot. According to Syfy.com, the comet that prompts the Alpha Monocerotid meteor shower is “on an orbit that’s much longer than 150 years, so it doesn’t pass by the Earth very often.” Astronomers hope to learn more about the comet through each visible meteor shower.
4. If Possible, Move Away From Bright City Lights to Watch the Meteor Storm & Prepare Early
Scientists Peter Jenniskens and Esko Lyytinen explained in a paper published in Meteor News that anyone hoping to see the unicorn meteor shower needs to be prepared ahead of time. They warn that if the shower is as big as they predict, it will be over remarkably quickly. They wrote, “Anyone who is going to try to observe should not be late at all. The strongest maximum would fit in about 15 minutes, or maybe a little bit less. It will be almost completely over in about 40 minutes.”
The shower is quick because the debris field left behind by the comet is not spread out. National Geographic explains that the “debris steam” is less than 32,000 miles wide. Jenniskens told the magazine, “Most years, our planet misses or grazes the meteor stream, but rarely, we actually plow through a denser part of the debris, and this can cause noticeably much more dramatic meteor activity in our skies.”
Astronomers recommend watching the unicorn meteor shower outside, far removed from bright city lights. It’s advisable to get outside early in order to allow your eyes to become accustomed to the dark. The moon isn’t expected to disrupt viewing, but cloudy skies certainly would block the show.
5. Skeptics Caution That the Unicorn Meteor Storm May Not Happen At All
It’s important to note that the expected unicorn meteor storm may not happen at all. The prediction is based on limited information about a mysterious comet and projections stemming from the last show in 1995.
Bill Cooke of the NASA Meteoroid Environment Office warns that, based on his own review of the evidence, “I now think there is a pretty good chance there may be no outburst at all. And even if there is, it won’t be as impressive as many think.”
Cooke explains that the intensity of the meteor shower “is very dependent on the size of the parent comet’s orbit. If it is much smaller, or larger, the distance from the stream center will be bigger, and there will not be any sky show, just the normal AMOs, puttering along with their normal rate of 3 or so meteors per hour. And since we have not yet discovered this mysterious parent comet, who knows how close the estimate of the orbit is to the actual?” You can read his full blog here.