{"id":17876,"date":"2026-09-27T09:12:59","date_gmt":"2026-09-27T07:12:59","guid":{"rendered":"https:\/\/deep-space-astronomy.ch\/?p=17876"},"modified":"2026-09-27T09:53:20","modified_gmt":"2026-09-27T07:53:20","slug":"orionides-21-22-octobre-2026-essaim-comete-halley-guide-observation","status":"publish","type":"post","link":"https:\/\/deep-space-astronomy.ch\/en\/orionides-21-22-octobre-2026-essaim-comete-halley-guide-observation\/","title":{"rendered":"Orionids, October 21\u201322, 2026: Halley\u2019s Comet\u2019s Meteor Shower\u2014An Observation Guide"},"content":{"rendered":"

The Orionids are the meteor shower originating from the most famous of all comets: 1P\/Halley. Every October, Earth passes through the dust trail left by Halley during its successive orbits around the Sun. The peak of the shower is expected on the night of October 21\u201322, 2026. The meteors are fast, sometimes bright, and some leave lingering trails. It is the second fall meteor shower after the Draconids on October 9.<\/p>\n

Where do the Orionids come from?<\/h2>\n

Halley\u2019s Comet (1P\/Halley) orbits the Sun approximately every 76 years. With each pass, it sheds dust grains that are scattered along its orbit. These grains travel through the Solar System at the same speed as the comet\u2014about 66 km\/s relative to Earth. When Earth passes through this dust stream, the grains enter the atmosphere at that speed, burn up, and create a shooting star.<\/p>\n

In 1705, Edmond Halley demonstrated that the comets observed in 1531, 1607, and 1682 were in fact the same comet, returning every 76 years. He predicted its return in 1758\u2014and the comet returned as predicted. Halley\u2019s last pass was in 1986. The next one is expected in 2061.<\/p>\n

The Orionids are not the only meteor shower originating from Halley's Comet. The Eta Aquarids, which occur in May, also originate from the same comet. Halley's Comet has thus left behind two dust trails that Earth passes through each year: one in the spring and one in the fall.<\/p>\n

Why is it a fast swarm?<\/h2>\n

At 66 km\/s, the Orionids are among the fastest meteors of the major annual meteor showers. By comparison, the Draconids (early October) enter at 20 km\/s, the Geminids (December) at 35 km\/s, and the Perseids (August) at 59 km\/s.<\/p>\n

This high speed has two consequences:<\/p>\n

    \n
  1. Persistent trails<\/strong> : Very fast meteors create columns of ionized gas in the upper atmosphere. These columns can remain visible for several seconds, or even a minute, after the meteor has passed. This is called a persistent trail.<\/li>\n
  2. Bright meteors<\/strong> : The kinetic energy of a meteoroid traveling at 66 km\/s is considerable. The Orionids regularly produce bolides\u2014meteors brighter than Venus\u2014and sometimes fireballs.<\/li>\n<\/ol>\n

    The ZHR (Zenithal Hourly Rate) of the Orionids is about 10 to 20 meteors per hour in a typical year. However, the Orionids are known for their variability: some years produce higher peaks, with observed rates of up to 30\u201350 meteors per hour. The American Meteor Society notes that the Orionids are a moderate-strength meteor shower that sometimes reaches high activity levels.<\/p>\n

    The Radiant: in Orion, but don't look there<\/h2>\n

    The radiant of the Orionids\u2014the point from which the meteors appear to originate\u2014is located in the constellation Orion, near the star Gamma Orionis (Bellatrix), on the hunter\u2019s right side.<\/p>\n

    But as NASA explains: don\u2019t look directly at the radiant. Meteors are visible across the entire sky. If you look directly at the radiant, the meteors will appear short\u2014this is a perspective effect called foreshortening. The best place to watch is 45 to 90 degrees from the radiant, where the meteors will appear longest.<\/p>\n

    From Switzerland, Orion rises in the southeast around 10:00\u201311:00 p.m. in late October. The radiant is high in the sky around 2:00\u20133:00 a.m. This is the best time for viewing: the radiant is high, and the meteors are clearly visible.<\/p>\n

    Moon Conditions in 2026<\/h2>\n

    In 2026, the full moon occurs on October 26 at 04:12 UTC. The peak of the Orionids (October 21\u201322) therefore occurs during a waxing gibbous moon, illuminated to about 76%. The Moon will be up for much of the night.<\/p>\n

    But there is some good news: the Moon sets several hours before dawn. According to EarthSky and the American Meteor Society, the best viewing window is during the dark hours before dawn\u2014after the Moon sets and before daybreak. This window lasts about 2\u20133 hours, between approximately 3:00 a.m. and 5:30 a.m. local time in Switzerland.<\/p>\n

    The gibbous Moon will reduce the number of visible meteors\u2014faint meteors will be obscured by the Moonlight. But bright meteors and fireballs will still be visible. And the Orionids produce precisely these bright meteors\u2014that\u2019s one advantage of their high speed.<\/p>\n

    How to Observe<\/h2>\n

    The equipment: your eyes<\/h3>\n

    As with the Draconids, the equipment is simple: your eyes<\/strong>. No binoculars, no telescope. Meteors are visible only to the naked eye, and the field of view of any instrument is far too narrow to capture a meteor shower.<\/p>\n

    Materials needed:<\/p>\n