Meteor Showers Explained: How They Form, Annual Peaks and How to Watch

On the night of October 21–22, 2026, Earth crosses one of the densest parts of the debris trail left by Halley's Comet, producing the annual Orionid meteor shower. According to the American Meteor Society (AMS), a waxing gibbous moon that is 74% illuminated will interfere with the view that night, cutting into what is normally a modest display of 10 to 20 meteors per hour. The Orionids are one of roughly nine recurring showers that NASA and the AMS track every year, each tied to a specific stretch of debris Earth passes through at the same point in its orbit.

How a meteor shower forms

NASA's Science division explains that meteor showers occur because comets, and in a few cases asteroids, leave a trail of dusty debris as they travel around the Sun. Most of the particles in that trail are no larger than a grain of sand or a pea. When Earth's orbit carries the planet through one of these debris trails, large numbers of the particles enter the atmosphere at once, and friction with the air heats them until they glow — the streaks commonly called shooting stars.

A single pass of a comet near the Sun can shed, in NASA's Jet Propulsion Laboratory's description, trillions of small particles, and that material can remain spread along the comet's orbital path for centuries. Because Earth follows essentially the same orbital path every year, it intersects the same debris streams at roughly the same calendar dates, which is why each shower returns on a predictable schedule.

The point in the sky from which the meteors appear to radiate — the feature that gives each shower its name — is an effect of perspective rather than a physical location. NASA's Space Place describes it this way: meteors "may appear anywhere in the sky, but their 'tails' all seem to point back to the same spot," because the particles are travelling on near-parallel paths before they strike the atmosphere. Showers are named for the constellation that sits closest to that radiant point, such as the Perseids (Perseus) or the Geminids (Gemini).

What causes the debris: comets versus one asteroid

Most major showers are linked to a specific comet. NASA's overview ties the Perseids to comet Swift-Tuttle, which orbits the Sun roughly every 135 years, the Leonids to comet Tempel-Tuttle, and the Eta Aquariids and Orionids to debris from comet Halley. The Taurids are associated with comet Encke.

The Geminids are the exception. JPL reports that astronomers traced the shower's debris to an object called 3200 Phaethon, which the agency describes as the remains of what it calls "a dead comet" rather than an active one. Researchers identified the link by matching the orbit of the debris stream to the orbit of Phaethon itself.

The year's major showers

Peak dates for most showers fall within the same few days each year; exact rates can vary. The American Meteor Society's 2026/2027 calendar gives specific 2026 dates and moon conditions for several upcoming showers, while NASA's overview lists the general annual timing. Expected rates below are given as zenithal hourly rate (ZHR) where available, drawn from EarthSky's 2026 shower guide or from the American Meteor Society; actual counts an observer sees are normally lower.

The AMS calendar also notes moon illumination for specific 2026 peak nights: 74% for the Orionids, 25% for the Southern Taurids, 4% for the Northern Taurids, and 15% for the Geminids — meaning the Geminids, described by the AMS as usually the year's strongest shower, will have comparatively dark, favorable skies in 2026.

How to watch a meteor shower

• No telescope or binoculars are needed; NASA's Space Place notes that this kind of equipment narrows your field of view and makes meteors harder to spot, not easier.
• EarthSky's 2026 guide recommends the hours after midnight and before dawn, when the radiant constellation is highest in the sky for most showers.
• A bright or full moon sharply cuts the number of meteors visible, according to both NASA's Space Place and EarthSky; a new moon or a moon that has already set gives the darkest, most favorable sky.
• Allow 20 to 30 minutes for your eyes to adapt to the dark, and avoid looking at phone screens during that time, per EarthSky's guidance.
• NASA's Space Place suggests lying down in an open area away from obstructions, bringing blankets or a sleeping bag for warmth, and relaxing your gaze rather than staring at one fixed point, since meteors can appear anywhere in the sky.
• Activity typically builds for a few nights before the stated peak and fades afterward, per JPL, so a night or two either side of the peak can still produce a reasonable show.

Why this matters now

With the Orionids peaking on October 21–22, 2026, it is the next scheduled shower on the 2026 calendar after the Southern and Northern Taurids pass in November and before the Geminids close out the year in December. The AMS calendar cautions that the 74% moon illumination expected during the Orionid peak will reduce how many of the shower's fainter meteors are visible, even though the shower's activity period extends over several weeks around the peak date.