The Draconis meteor shower is expected to take place between October 6 and 10 – a skylight display known to be temperamental and inconsistent.
Meteor showers are celestial events that occur when Earth passes through cosmic debris streams that leave behind comets and, in some rare cases, asteroids. During these events, numerous meteors can be seen streaking across the sky, appearing to originate from a single point – known as a radiant.
Meteors—colloquially referred to as shooting stars—are the streaks of light we see in the sky when tiny fragments of space debris burn up in Earth’s atmosphere at high speed.
The Draconids are an irregular, relatively quiet meteor shower that on rare occasions produces very strong activity.
The Draconids are only active for a relatively short time – their normal range is between October 6 and 10, according to the Royal Greenwich Observatory in London, UK. By comparison, many other meteor showers last several weeks.
The date of peak activity is October 8, but meteor rates are not expected to be high this year, according to the International Meteor Organization (IMO) calendar. The light from the near-full moon will also be a big obstacle for those trying to observe the event.
“This year [the IMO] states that there is no expectation of unusual activity from the Draconids, so a theoretical peak rate of 10 meteors per hour is expected, which in practice means an observer might see four,” Robert Massey, deputy executive director of the UK’s Royal Astronomical Society . he said Newsweek. “But this will be made more difficult by the light from the near-full moon, so casual observers may not notice much at all,” he said.
Tania de Sales Marques, an astronomer at the Royal Observatory, said Newsweek: “The Draconids may be bright, but they will be difficult to spot as the full moon will be open all night, lighting up the sky. We expect only 10 meteors per hour at most in this year’s display.”
Occasionally, however, the Draconids, best seen from the northern hemisphere, spring a surprise and produce large numbers of meteors—up to 1,000 in an hour.
“The Draconids are usually pretty quiet with only a few meteors per hour, but occasionally they put on big displays,” Massey said. “So for example in 1933 an observer at Armagh Observatory [in Northern Ireland] he said they fell like snowflakes. That said, IMO don’t expect anything out of the ordinary this time around.”
The best time to see Draconids is in the evening after dusk—this is different from most other showers, which are best seen in the early morning hours.
The Draconids are the result of Earth passing through debris streams left behind by comet 21/P Giacobini-Zinner. This object is a relatively small comet with a nucleus that is about 1.2 miles in diameter.
“It will then pass the perihelion – its closest point to the sun – in 2025 and completes an orbit every 6.6 years,” Massey said.
Giacobini-Zinner is notable for being the first comet visited by a space probe, when the International Cometary Explorer flew by in September 1985.
The rate of meteors during the peak of the Draconid shower depends on which part of the comet’s tail Earth passes through in any given year.