How to see the November Leonid meteor shower: What to know

The Leonids are a prolific annual meteor shower associated with the comet Tempel–Tuttle, and are also known for their spectacular meteor storms that occur about every 33 years. The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to radiate from that point in the sky. The name is derived from Greek and Latin with the prefix Leo- referring to the constellation and the suffix -ids signifying that the meteor shower is the offspring of, descendant of, the constellation Leo.

What is the Leonid meteor shower — and what should you expect?

According to scientists, the Leonid meteors are fast-moving, bright pieces of space debris that come from the Earth’s northern hemisphere and the constellation Leo. The bits of rubble are remnants of the Tempel-Tuttle comet interacting with the Earth’s atmosphere and then whizzing by. Due to the retrograde orbit of 55P/Tempel-Tuttle, the Leonids are fast moving streams which encounter the path of Earth and impact at 70 km/s (252,000 km/h; 156,590 mph). It is the fastest annual meteor shower. The annual show contains nearly 100 to 200 meteors during each shower.

Peak Timing and Visibility

The astrological wonder started Nov. 3 and is expected to last through the end of the month, according to scientists at the Weather Channel. The Leonid meteor shower is set to reach its peak Thursday night, Nov. 17, and especially between midnight and dawn Friday. While there is no rock-solid start time, most star-gazers have agreed that the ideal viewing conditions will be at midnight. Experts have said that the colorful meteor shower can be best viewed from the darkest area possible, but everyone in the world will be able to take part in viewing this heavenly wonder without having to possess any binoculars.

Approximately 10 to 15 Leonid meteors will pass every hour at the peak of the storm, according to the Weather Channel. Leonid meteors travel so close to the horizon that they have been nicknamed “Earth-grazers.”

Scientific Properties and Meteoroids

Earth moves through meteoroid streams left from passages of a comet. The streams consist of solid particles, known as meteoroids, normally ejected by the comet as its frozen gases evaporate under the heat of the Sun once within Jupiter's orbit. Larger Leonids which are about 3⁄8 in across have a mass of 0.5 g (0.02 oz) and are known for generating bright (apparent magnitude −1.5) meteors.

Key Leonid Statistics

• Discovery date: 902 AD (first record)
• Parent body: 55P/Tempel–Tuttle
• Radiant: Constellation Leo
• Velocity: 70–71 km/s
• Zenithal hourly rate: 15
• Next major occurrence: The next Leonid meteor is scheduled to occur in 33 years in 2055.

Meteoroid Size and Brightness Comparison

• Size 2 mm: Apparent Magnitude +3.7 (Comparable to Delta Ursae Majoris)
• Size 1 cm: Apparent Magnitude -1.5 (Comparable to Sirius)
• Size 2 cm: Apparent Magnitude -3.8 (Comparable to Venus/Fireball)

Historical Context and Meteor Storms

The Leonids are famous because their meteor showers, or storms, can be among the most spectacular. Because of the storm of 1833 and the developments in scientific thought of the time, the Leonids have had a major effect on the scientific study of meteors, which had previously been thought to be atmospheric phenomena. It was the meteor storm of November 12–13, 1833 that broke into people's modern-day awareness. One estimate of the peak rate is over one hundred thousand meteors an hour, while another, done as the storm abated, estimated in excess of 240,000 meteors during the nine hours of the storm, over the entire region of North America east of the Rocky Mountains.

Old trails are spatially not dense and compose the meteor shower with a few meteors per minute. Conversely, young trails are spatially very dense and the cause of meteor outbursts when the Earth enters one. The Leonids also produce meteor storms (very large outbursts) about every 33 years, during which activity exceeds 1,000 meteors per hour, with some events exceeding 100,000 meteors per hour.