Leonid Meteor Shower to Coincide With Partial Lunar Eclipse This Week

The Leonid meteor shower will peak later this week, shortly before a partial lunar eclipse graces the skies.

In 2021, the Leonids are active between around November 3 and December 2, with the peak expected on the night of November 17-18 between midnight and dawn, according to the American Meteor Society (AMS.)

The Leonids are characterized by fast, bright meteors, many of which have persistent trains—trails of vaporized material that glow in the sky.

In ideal conditions—when the shower is viewed from a rural location with a dark sky—it is possible to see between 10 and 15 Leonid meteors per hour around the time of the peak.

But in 2021, the moon will be 98 percent full on the night of the peak, hampering observations of the shower. The relatively strong moonlight will likely wash out some of the fainter meteors, making it harder to view the event.

Meteor showers are celestial events in which numerous meteors—colloquially known as "shooting stars"—appear in the sky, seemingly originating from a single point. This point is known as the radiant, which in the case of the Leonids, lies in the constellation Leo—hence the name.

Meteor showers occur when the Earth passes through streams of cosmic debris left behind by comets—and in some rare cases, asteroids—as they orbit the sun. In the case of the Leonids, the debris originates from the comet 55P/Tempel-Tuttle,

Meteors are the streaks of light that we see when small pieces of space debris enter the Earth's atmosphere, burning up at high speeds. In fact, Leonid meteors can travel at speeds of around 156,000 miles per hour.

The Leonid meteor shower doesn't usually produce very high rates of visible meteors. But on rare occasions, the shower produces spectacular meteor storms, characterized by hundreds or even thousands of visible meteors per hour.

The peak of the Leonids comes just before a partial lunar eclipse, which will be visible across much of the globe on the night of November 18-19.

Partial Lunar Eclipse

The event will be the last lunar eclipse of 2021, and the longest partial lunar eclipse in almost 600 years, with the whole event lasting for around six hours—although observers in some locations may only be able to see parts of it.

Partial lunar eclipses occur when the Earth passes between the sun and the full moon, but they are not precisely aligned. During these events, only parts of the visible face of the moon are plunged into the darkness created by the Earth's shadow.

While the latest eclipse will only be partial, observers in most locations will be able to see up to 97 percent of the moon's visible surface fall into the Earth's shadow.

People in North America are ideally placed for the whole of the eclipse, depending on local weather conditions. But at least parts of the eclipse will also be visible from vast swathes of the globe, including South America, Australia, much of Europe and Asia, and parts of northwest Africa.

For observers on the U.S. East Coast, the partial eclipse will begin shortly after 2 a.m. local time on November 19, according to NASA, and will reach its maximum at around 4 a.m. For those on the West Coast, the eclipse will begin just after 11 p.m. local time on November 18, before reaching a maximum at 1 a.m.

A meteor shower
A file image of shooting stars during a meteor shower. The Leonid meteor shower will peak on the night of November 17-18. iStock