The Quadrantids meteor shower

Key facts

Peak

around 3–4 January

Active

late December to about 12 January

Rate at peak (ZHR)

about 80 (variable; roughly 60 to 200)

Speed

41 km/s

Radiant

Boötes (between the end of the Plough's handle and the head of Draco)

Parent body

Asteroid 2003 EH1 (probably a dormant or extinct comet)

Dates shift slightly from year to year. This year's peak is in the events calendar.

The Quadrantids open the meteor year, and on a clear, frosty night they can rival the Perseids and Geminids. The catch is that their peak is short and sharp: the best activity usually lasts only a few hours, so a cloudy spell or a badly timed maximum can make the shower seem to vanish.

The name is a fossil from an old star map. In 1795 the French astronomer Jérôme Lalande introduced a constellation called Quadrans Muralis, the Mural Quadrant, named after an instrument used for measuring star positions. The shower's radiant (the point in the sky from which the meteors appear to stream) lay inside it. The International Astronomical Union did not keep Quadrans Muralis when it fixed the official list of 88 constellations in 1922, and that patch of sky now belongs to Boötes, the Herdsman. The shower kept its old name anyway. It was first described as an annual display in the 1830s, when observers in Europe and North America noticed a burst of meteors in early January.

For more than a century the parent body was a mystery. Most showers come from comets, which shed trails of dust as they warm near the Sun. In 2003 a small object called 2003 EH1 was discovered, and its orbit turned out to match the Quadrantid stream closely. It looks like an asteroid, showing no tail, but many astronomers think it is a dormant or extinct comet that has lost most of its ice. Some researchers have linked it to a comet seen by Chinese, Japanese and Korean observers in 1490, though that connection remains uncertain.

The narrow peak tells us something important. A broad, long-lasting shower comes from an old stream of dust that has had time to spread out. The tight Quadrantid maximum suggests a relatively young stream, perhaps only a few centuries old, which has not yet been smeared out by the gravity of the planets.

What to expect. Under a dark sky at the peak, a single observer might see perhaps 25 to 50 meteors an hour, sometimes more in a strong year, because real counts are almost always lower than the ZHR (the Zenithal Hourly Rate, an idealised figure for a perfectly dark sky with the radiant overhead). Quadrantids are medium-speed meteors, often bluish, and the shower produces some bright fireballs. Because the stream is so narrow, the timing matters enormously: if the peak falls during your daylight, you may see only a scattering.

Viewing from the UK. The UK is well placed. The radiant lies in the northern sky, low in the north in the evening and climbing high towards the east before dawn. The hours after midnight until morning twilight are usually best, especially if the predicted peak falls then. January nights are long but bitterly cold, so dress as if for a winter walk and then add another layer. A reclining garden chair, a sleeping bag and a flask of something hot make a big difference.

Viewing worldwide. The Quadrantids are very much a northern hemisphere shower. From the tropics they are weak, and from much of the southern hemisphere the radiant barely rises. North America, Europe and northern Asia have the best chance, and observers across several longitudes can combine to catch the brief peak.

Dates and peak times shift slightly from year to year, so check a current meteor calendar a few days ahead and note the predicted time of maximum.

Viewing tips

1. Check the predicted peak time for your year, because the best activity lasts only a few hours.
2. Watch after midnight, when the radiant in Boötes climbs higher in the north-eastern sky.
3. Dress for deep cold: hat, gloves, thick socks and a sleeping bag over your legs.
4. Look about halfway up the sky and slightly away from the radiant, not straight at it.
5. Give your eyes at least 20 minutes in the dark and avoid looking at a bright phone screen.

Read about the parent: 2003 EH1, the Quadrantid parent, and the other comets behind meteor showers.