Orionid meteor shower peaks Monday with 10-20 meteors per hour

Monday night, if the clouds stay away, the sky will fill with streaks of light. The Orionid meteor shower reaches its peak at 8 p.m. Eastern time, and under clear conditions, observers looking south can expect to see between 10 and 20 meteors per hour—bright enough that some will leave glowing trails hanging in the darkness for a moment after the meteor itself has burned away. The display is occasionally dramatic enough to produce fireballs, those rare, brilliant flares that catch the eye even in peripheral vision.

The timing this year carries an advantage. A new moon coincides with the peak, meaning the dark side of the moon faces Earth and won't wash out the fainter meteors with reflected sunlight. This is the kind of astronomical luck that doesn't happen every year. Robert Lunsford, who coordinates fireball reports for the American Meteor Society, notes that the peak itself isn't sharp—the shower doesn't arrive and depart like a scheduled train. If Monday night brings clouds, the activity continues. Tuesday morning, or even Wednesday, will show nearly the same intensity. The window for viewing stretches across several nights.

These meteors are fast-moving, most visible for only a fraction of a second. The brighter ones, though, leave behind what Lunsford calls persistent trains—smoke trails that linger in the upper atmosphere after the meteor has vanished. Viewing is best from the southern sky, ideally around 10 p.m. Monday night or between 4 and 5 a.m. Tuesday morning in your local time zone. The earlier morning hours often offer clearer skies and less light pollution.

The Orionids originate from debris scattered by Halley's Comet. Earth passes through this debris field twice each year as it orbits the sun. In October, the encounter produces the Orionids, which radiate from the Orion constellation. In May, the same comet's trail creates a different shower, the Eta Aquariids, which appears to shoot from a different part of the sky. Halley's Comet itself last appeared in 1986. Its orbital period spans roughly 76 years, so astronomers expect it to return to Earth's view in 2061.

This week also brings a complication—or perhaps an opportunity. The Southern Taurids are simultaneously active, expected to peak around November 4 and 5. These meteors move more slowly than the Orionids and originate from the constellation Taurus, farther west in the sky. Lunsford describes the effect with a touch of poetry: the slow Taurids shoot eastward toward Orion while the fast Orionids shoot westward toward Taurus, as if the two showers are doing battle across the night sky. Observers patient enough to watch for extended periods might catch both displays overlapping.

For those who miss the Orionids, the autumn and winter sky holds more celestial events. The Northern Taurids peak November 11 and 12. The Leonids arrive November 16 and 17. December brings the Geminids on the 13th and 14th, and the Ursids close out the year on December 21 and 22. Two supermoons round out the calendar—a Beaver Moon on November 5 and a Cold Moon on December 4. The night sky, it turns out, is never empty of events for those willing to look up.