Ursids Meteor Shower — Peak 2026-12-22

Meteor showers are celestial events where multiple meteors appear to radiate from a single point in the night sky. They occur when Earth passes through the debris trail left by a comet or, in some cases, an asteroid. As these tiny particles — often no bigger than a grain of sand — enter Earth's atmosphere at high speed, they vaporise and create the bright streaks of light we call meteors or 'shooting stars'.

The radiant point is the apparent direction from which all meteors in a shower appear to originate. This is a perspective effect — like driving through a snowstorm and seeing all the flakes appear to come from a point ahead. The Zenithal Hourly Rate (ZHR) is the theoretical maximum number of meteors an observer would see under perfect conditions with the radiant directly overhead. Actual observed rates are typically lower due to light pollution, moonlight, and the radiant's position in the sky.

Most major meteor showers are annual events, recurring when Earth revisits the same debris stream each year. The peak date remains consistent from year to year, though the intensity can vary based on the density of the debris trail and whether Earth passes through the centre or the edge. Some showers, like the Leonids, occasionally produce spectacular outbursts or storms when the parent comet has recently passed through the inner solar system.