Rare 'Unicorn Meteor Storm' of Hundreds of Shooting Stars per Hour Predicted, but Experts Are Skeptical

Astronomers are forecasting an intense, blink-and-you'll-miss-it 'unicorn meteor storm' on November 21, with predictions suggesting there could be as many as 1,000 meteors an hour at its peak.

However, others have warned stargazers not to get too carried away—or they could be in for a disappointment.

The Alpha Monocerotids takes place every year around November 21, producing a modest display consisting of just a few meteors. Every now and then, however, the Alpha Monocerotids produce a more impressive "outburst," and its hourly meteor rate shoots up to a number in the hundreds.

This happened in 1925, 1935, 1985 and 1995, and according to meteor scientists Peter Jenniskens and Esko Lyytinen, it could happen again this year.

Writing in Meteor News, Jenniskens and Lyytinen say the number of meteors any one observer could expect to see in a given hour could range from "maybe only about a hundred to even storm level," with an hourly rate of more than 1,000.

However, these numbers are contingent on the sky being clear, the radiant directly overhead and on having an omnipresent view in all directions.

"Because the radiant is not very high and also because of the possible twilight, the actual counts will be of course well below this level," the researchers add.

Constellations of Monoceros the Unicorn
Constellations of Monoceros the Unicorn, Canis Major and Minor from A Celestial Atlas by Alexander Jamieson. The 1995 outburst helped pinpoint the radiant of the Alpha Moncerotids, which lies within the borders of the constellation known as Canis Minor, near the bright star Procyon. © Historical Picture Archive/CORBIS/Corbis/Getty

Not everyone is convinced the display will be quite as impressive as the paper and some media headlines would suggest.

Bill Cooke, the lead of NASA's Meteoroid Environment Office, wrote "skepticism kicked in" after some time spent "dumpster diving" through old papers.

"I now think there is a pretty good chance there may be no outburst at all," Cooke wrote in a blog post for NASA. "And even if there is, it won't be as impressive as many think."

His reasoning is that the paper relies on the assumption that the Earth was "forced to pass through the center of Alpha Monocerotid meteor stream (AMOs for short)" during 1925 and 1935 outbursts, which has not been proven. Scientists also have no idea of shower's parent comet's orbit—or even the parent comet itself.

If Jenniskens and Lyytinen's calculations about the parent comet having a 500-year orbit around the sun are correct, Cooke writes "we should pass very close to the center of the meteor stream this year, missing it by a scant 15,000 miles."

"That's just a tad closer than we got back in 1995, when the observed...rate was about 400 per hour. And it's why the forecast rate is so high—closer means the same intensity or better."

Viewing the Alpha Monocerotids

The Alpha Moncerotids appear to radiate from the constellation Monoceros, which is Greek for "unicorn." However, according to the American Meteor Society, the 1995 outburst confirmed the radiant lies within the borders of the constellation known as Canis Minor, near a star called Procyon.

This year, the meteor shower is predicted to start from approximately 11.15 p.m. ET and last between 15 and 40 minutes, but could start up to an hour earlier.

"Potential observers are encouraged start viewing the sky at least an hour before the predicted time of maximum activity in case the timing estimates are in error," said Robert Lunsford in an article for the American Meteor Society.

"If the moon is above the horizon from your location then move your view more toward the west to keep it out of your field of view."

People near the East Coast will be in best position to view the outburst, though it can be viewed as far west as Wyoming and Colorado. To find out how your location might affect your viewing, check out the map provided by NASA.

To make the most of the experience, find a dark place away from city lights, give yourself half an hour or so to adjust to the darkness, keep warm and be patient.

"If Jenniskens and Lyytinen are right, you might see some pieces of a comet that awaits discovery, burning up in the atmosphere 60 miles above your head," wrote Cooke.

"That's worth a couple of hours, I think. Even if there is no outburst, it doesn't hurt to get out under the stars for a bit."

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