Unicorn Meteor Shower: Video, Images Show Alpha Monocerotids Outburst

Last night, the so-called "Unicorn" meteor shower produced an outburst of shooting stars, although at a far lower rate than some experts had predicted.

According to the American Meteor Society, a subdued outburst occurred at around 04:50 a.m. UT, or 11:50 p.m. EST. Only about a dozen meteors could be seen in the 20 minutes or so that the shower was active.

In the video below, the outburst can be seen starting at around the 4:12:00 mark.

The Unicorn meteor shower, otherwise known as the alpha Monocerotids, are active every year, producing a few meteors around November 22. These meteors travel at around 65 kilometers per second, or around 145,000 miles per hour.

Normally, the shower produces a low hourly rate of meteors. But some years have produced particularly notable outbursts, including 1925, 1935, 1985, and 1995. During the latter outburst, the peak hourly rate of meteors was estimated to be around 400. Meanwhile, in 1925 and 1935, this hourly rate was more than 1,000.

Before last night's outburst, astronomers Peter Jenniskens and Esko Lyytinen predicted that the hourly rate could be anywhere from a hundred to a thousand, Meteor News reported.

However, Bill Cooke from NASA's Meteoroid Environment Office, was skeptical of these claims.

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

The alpha Monocerotids appear to originate, or radiate, from a point in the sky between the constellations Canis Minor and Monoceros—which is Greek for "unicorn." They differ to most meteor outbursts—which last for several hours—because any strong activity is usually over within an hour.

Meteor showers are celestial events during which numerous meteors appear in the night sky, originating from what seems like a single location. They occur when the Earth passes through streams of cosmic debris left behind by comets and asteroids.

In the case of the alpha Monocerotids, the body responsible for the debris is not currently known, although astronomers think it is likely a long-period comet—those which take more than 200 years to complete one orbit around the sun.

Meteors, commonly known as "shooting stars," are the streaks of light we see when small pieces of debris from these asteroids or comets enter the Earth's atmosphere and burn up at extremely high speeds. Before meteors enter the atmosphere, they are known as "meteoroids."

The vast majority of meteors burn up before they hit the ground. However, if one does reach the planet's surface it is known as a meteorite.