The 2019 Alpha Monocerotid Meteor Storm

Meteor shower (Getty, Sky2014)

On Thursday night into Friday morning, November 21-22, the obscure Alpha Monocerotid shower could produce upwards of 400 meteors per hour from a radiant near the star Procyon, a star near the constellation Monoceros, the unicorn.

Peter Jenniskens, a senior research scientist with the SETI Institute and NASA’s Ames Research Center, along with Esko Lyytinen of the Finnish Fireball Network, have been keeping tabs on the shower for years. During outbursts, such as those that occurred in 1925 and 1935, activity reached meteor-storm levels with a zenithal hourly rate (ZHR) of more than 1,000.

Activity rose to near-storm levels again in 1985 and 1995 with ZHRs around 700 and 400. ZHR is an idealized number based on how many meteors a single observer would see if the radiant were overhead in a dark sky during shower maximum.

What is a Meteor Storm?

A meteor storm is when a dust trail from a meteor shower is small and dense. The result is hundreds and even thousands of meteors burning up in just minutes,” according to the National Weather Service.

According to the American Meteor Society, a meteor shower is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth’s atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller than a grain of sand, so almost all of them disintegrate and never hit the Earth’s surface.

Intense or unusual meteor showers are known as meteor outbursts and meteor storms, which may produce greater than 1,000 meteors an hour.

Alpha Monocerotid Meteors

This map shows the sky facing southeast from Philadelphia at 11:50 p.m. EST on Nov. 21. Two Alpha Monocerotid radiants are marked, 1985 and 1995. The 1995 radiant was determined by multi-station photography. Image: Sky & Telescope
This map shows the sky facing southeast from Philadelphia at 11:50 p.m. EST on Nov. 21. Two Alpha Monocerotid radiants are marked, 1985 and 1995. The 1995 radiant was determined by multi-station photography. Image: Sky & Telescope

The source of the Alpha Monocerotids is unknown, according to Sky & Telescope, but the stream’s orbital characteristics point to a long-period comet with a period of about 500 years. This nameless visitor deposited a dense, narrow ribbon of debris in the distant past with a half-width of only around 55,000 kilometers, equal to the distance from the center of Earth to the geostationary satellite belt.

Where Do Meteors Come From?

As the Earth travels through leftover comet or astroid debris, we see "fireballs" or meteors streaking through the night sky as the debris burns up upon entry into the atmosphere. Image: Accuweather
As the Earth travels through leftover comet or astroid debris, we see “fireballs” or meteors streaking through the night sky as the debris burns up upon entry into the atmosphere. Image: Accuweather

Meteors come from leftover comet particles and bits from broken asteroids. When comets come around the sun, the dust they emit gradually spreads into a dusty trail around their orbits. Every year the Earth passes through these debris trails, which allows the bits to collide with our atmosphere where they disintegrate to create fiery and colorful streaks in the sky.

The Alpha Monocerotid’s Peak

Time: Get set up by 12:15 AM. Meteor Storm begins at 12:30 AM through 1:10 AM.
Where to look: Towards the Southeast.

Jenniskens and Lyytninen expect Earth to barrel through the swarm of cometary dust bunnies on the night of November 21-22, centered on 4:50 Universal Time on November 22nd (12:50 AM AST on November 22nd). Circumstances are nearly identical to the 1995 outburst when the ZHR briefly reached 400. Depending on exactly how close Earth passes to the center of the debris trail we could see storm rates like those in 1925 and 1935 — years when Earth presumably shot directly through the center — or “scraped bottom” with counts closer to 100 meteors an hour.

The radiant, located in eastern Monoceros, rises around 11 PM local time, so it will be relatively low in the eastern sky for observers in the eastern Caribbean at shower maximum.

Conditions for Viewing

The shower’s brevity means you don’t want to be late to the show. Past observations indicate that peak activity will last a mere 15 to 40 minutes! Lyytinen recommends getting out no later than 4:15 UT, Nov. 22nd (12:15 AM AST on Nov. 22nd) and look towards the southeast!

But, there are lots of impediments for viewing in Trinidad and Tobago.

Firstly, light pollution is a major issue in most populated areas across Western and Northern Trinidad, as well as the Western half of Tobago. Unfortunately, there is little you can do about this beyond traveling into darker areas such as parts of Northern Coastal Trinidad, or Eastern and Southern parts of the island.

Secondly, cloud cover. Models continue to indicate that clouds will be a major issue throughout Thursday night into Friday morning, with even isolated showers favoring Northern Trinidad and Tobago.

For the best chances, head to Eastern coastal Trinidad to limit your light pollution, but as mentioned, cloud cover will be a major impediment.

Lastly, the moon. Presently, we’re moving away from the third quarter phase of the moon which occurs tonight, moving into the new moon phase which is expected to occur on the 26th of November. Hence, no worries about the Moon — the 22%-illuminated crescent won’t rise until after 3 AM local time.

It’s Meteors – Not an Asteroid to Comet

Down-to-earth Journey of a Meteor Image: Space.com
Down-to-earth Journey of a Meteor Image: Space.com

It may be self-explanatory, as it is literally in the name of the shower, but the “shooting stars” you may see in the skies over the next several nights are meteors.

The terminology of these space objects matter, as a meteorite would have impacts to land, while a meteor does not.

Have you ever wondered what’s the difference between a meteor and a meteorite or an asteroid, meteoroid or comet? Here are the answers to all your questions regarding Meteor Terminology. Image: Vincent Perlerin/AMS

Meteor and meteorite strikes are more common than you might think. Dust-grain size meteoroids strike the Earth’s atmosphere almost constantly, but they often go unnoticed. Meteoroids between a millimeter and a centimeter burn up in the atmosphere and appear to us as shooting stars.

Larger strikes are less common—a one-meter meteoroid strikes the Earth once each year on average and would reach the ground as smaller debris, while a 100-meter meteoroid strikes the Earth approximately every 10,000 years, according to a Tufts University fact sheet. Meteoroids over 1 kilometer hitting Earth are catastrophic events that occur every 1 million years on average.

Meteoroids do not discriminate where they land, nor where they enter the earth’s atmosphere. Hence, it is well within the realm of possibility that events such as this could happen across Trinidad, Tobago or any of the other Caribbean islands.

But medium-size strikes can be dramatic spectacles—and in some cases, dangerous. The Chelyabinsk meteor that struck southern Russia in February 2013 blew out windows and caused indirect injuries to almost 1,500 people.

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