Ursid meteor shower at a glance
| Detail | Value |
|---|---|
| Activity window | about December 17 to December 26 |
| Peak | around December 22 |
| Zenithal hourly rate (ZHR) | about 10 (occasionally higher) |
| Radiant | Ursa Minor, near the star Kochab |
| Parent body | comet 8P/Tuttle |
| Entry speed | about 33 km/s |
These values follow the International Meteor Organization (IMO) calendar. For the complete list, see the meteor shower calendar.
A quiet shower near the solstice
The Ursids arrive a week after the Geminids, the richest shower of the year, and are easily overlooked. In most years the ZHR is only about 10, which from a dark site means a handful of meteors per hour. Still, the shower has a distinct character. Its radiant is close to the north celestial pole, so for observers at mid-northern latitudes it never sets. That means Ursids can be seen at any hour of the night.
The peak falls close to the December solstice, when nights in the Northern Hemisphere are at their longest. That gives you many dark hours, weather permitting.
Parent comet and outbursts
The Ursids come from comet 8P/Tuttle, which orbits the Sun about every 13.6 years. Its debris forms trails along its orbit, and in some years Earth passes through a denser part. Observers recorded strong displays in 1945 and 1986, and smaller enhancements have been seen in other years. These events are hard to predict and usually brief, but they show that the Ursids can be more than a footnote.
Ursid meteors enter at about 33 km per second, a medium-slow speed. They tend to be fairly faint.
Where to look
The radiant lies near Kochab, the brighter of the two stars at the end of the Little Dipper’s bowl, not far from Polaris. To find it, locate Polaris, the North Star, then look for Kochab a short distance away. The radiant is highest in the hours before dawn, so the early morning is usually best, although activity is possible all night.
Meteors can appear anywhere in the sky. Watch a broad area, and trace the path of each meteor back to see whether it comes from near the Little Dipper.
Moonlight
With such a low rate, a bright Moon can hide most Ursids. Check the moon phases for late December and the moonrise and moonset times where you are. If the Moon is up for part of the night, plan to watch during the darkest hours.
Viewing tips
- Face north. The radiant is in the northern sky; look up from there.
- Dress for winter. December nights are cold in the Northern Hemisphere. Layers, a hat and gloves are essential.
- Find a dark site. Many Ursids are faint, so light pollution hides them easily.
- Let your eyes adapt. Allow 20 to 30 minutes and avoid bright screens.
- Keep expectations modest. A few meteors an hour is a normal Ursid night.
- Combine with the season. The long nights around the holidays are a good time to explore the sky.
For more on what else is visible, see the sky tonight.