Mysterious Comet Debris May Spark 'Unicorn Meteor Storm'

An illustration of a meteor outburst. According to experts, a similar scene may unfold in the early morning hours of Nov. 21/22 as the Earth passes through debris left behind by a mysterious comet. (Photo: By SKY2015/Shutterstock)

If the idea of shooting stars too innumerable to count sounds like a brilliant experience worth staying up for, losing a bit of shut-eye on the evening of Nov. 21 may just be worth the price of admission.

Renowned meteor experts Peter Jenniskens and Esko Lyytinen say a wildcard meteor shower known as the alpha Monocerotids has the potential this year to transform into a "meteor storm," with shooting stars in excess of 400 per hour. According to the pair, such an outburst from the a-Monocerotids would be only the fifth ever recorded.

"This shower has previously produced four outbursts, in 1925, 1935, 1985 and 1995, of which 1995 was already predicted and the photographic observations revealed the exact radiant," they write. "This is important for modeling."

Look to the unicorn

The constellation Monoceros, easily visible to the naked eye, lies to the right of the constellation Orion.
The constellation Monoceros, easily visible to the naked eye, lies to the right of the constellation Orion. (Photo: Till Credner [CC BY-SA 3.0]/Wikimedia Commons)

The a-Monocerotids are nicknamed the "unicorn meteor shower" because they appear to radiate from Monoceros, a constellation that is Greek for unicorn. Like other more well-known annual meteor showers, they occur as a result of the Earth passing through debris trail left by comets. According to Jenniskens and Lyytinen, the unknown comet responsible for the a-Monocerotids may pass by Earth only once every 600 years.

"This dust trail exists for such a long time near the Earth’s orbit that it can produce outbursts, for at least decades, and in this case probably for a few centuries," they add. "The width of the trail is just very narrow. The half-width is approximately the same as the distance from the center of the Earth to the geostationary satellite orbit."

The small width of a-Monocerotids' debris trail means the spectacle has little forgiveness for tardiness. While the Earth can sometimes take days to pass through the debris trails of other comets, it will clear this one in as little as 40 minutes. Lyytinen recommends getting outside no later than 11:15 p.m. EST on the evening of Nov. 21, with a peak display expected around 11:50 p.m. EST.

Should the a-Monocerotids deliver, where would they rank in the pantheon of exceptional meteor outbursts? While 400 shooting stars per hour is incredibly rare, it pales in comparison to what happened on the evening of Nov. 12, 1883. In what many astronomers regard as the greatest single meteor shower of modern times, an estimated 100,000 or more shooting stars per hour saturated the night sky.

"Upwards of 100 lay prostrate on the ground...with their hands raised, imploring God to save the world and them," one account from South Carolina described. "The scene was truly awful; for never did rain fall much thicker than the meteors fell towards the Earth; east, west, north and south, it was the same."

Wishing you clear skies!