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If you are a meteoric fan, write Monday night (October 8th) on your calendar, especially if you live in the mid-Atlantic or northeastern United States, as well as in the Maritimes. eastern Canada. That night, the Earth will go through the irregular and surprised Draconid meteor shower.
The annual Draconid meteor shower occurs every year around October 8th when the Earth crosses a stream of dust from the periodic comet 21P / Giacobini-Zinner, which we will now call comet G-Z. so named because the meteors seem to emanate from the constellation Draco, the Dragon.
If you live elsewhere in the rest of North America, the expected peak of this meteorite rain will occur during the afternoon. Therefore, at dusk, you will be looking for possible latecomers of the display – if there is any visible left at all. [Draconid Meteor Shower 2018 Guide: When and How to See It]
The best-known meteor show in October is the Orionid shower, which peaks around October 21st and is one of the most reliable annual displays. This year, however, the draconian shower is the joker. As a general rule, in most years, there are hardly any draconian meteors, but draconids have a Jekyll-and-Hyde personality.
A notable meteoric activity appears to occur when the Earth just passes into the orbit of Comet G-Z shortly after the comet's passage. In 1933 and 1946, skywatchers were dazzled by "storms" of amazing meteors that produced thousands of meteors at the time. During these years, the Earth traversed particularly dense filaments of dusty debris that the comet had thrown in previous flights around the sun. The Draconides have not seen this kind of performance since, although rates have reached hundreds of dollars per hour in 1985, 1998 and more recently in 2011.
When and where to look
As I mentioned above, the evening of Monday, October 8th is the time to watch this year. New England and the Canadian Maritime Provinces seem well placed to have the best chances. [How to See the Best Meteor Showers of 2018]
Unlike most meteor showers, Draconids are at their best in the evening rather than after midnight. Their radiant (apparent point of origin dying at perspective) in the constellation Draco is high in the northwest sky when night falls; it sinks all night and gets closer to the horizon at dawn.
Start looking at the sky above as soon as it gets dark. No special equipment is needed – an unobstructed view of the sky, a reclining garden chair or floor cover, a watch and a notebook or tape recorder to keep track of Draconides seen.
The radiance of the shower is close to Draco's diamond-shaped head, the Dragon. A shower member is a meteor whose path, if drawn quite far back, would seem to come from this place. The meteors themselves can appear anywhere in the sky.
The draconid meteors seem to arrive from the north, almost perpendicular to the plane of the solar system; the north pole of the ecliptic (actually, the north pole of the solar system) lies at Draco. Meteors seem to be moving slowly, their speed of entry of 12 km / s (20 km / s) being among the slowest meteor showers.
Alastair McBeath, British meteorite astronomer: "Poets among us might like to think of this as" dragon tears "or as a blast of fire."
Stormy weather in 2018?
In October 1998, I wrote a feature article for the Sky & Telescope magazine on Draconid meteor shower. With the help of data provided courtesy of Donald K. Yeomans, from NASA's Jet Propulsion Laboratory at the time, I created a diagram illustrating where meteoroids had apparently been. the thickest around comet GZ.
The distance between the two orbits at the nodal crossing point is drawn vertically, and the moment the Earth passes past this point, in front of or behind the comet, is drawn horizontally. Eighteen past games are drawn. The main rains of 1933, 1946, 1985 and 1998 are represented by stars, small rains by points and years of low or no activity reported by open circles.
Looking back in 20 years, I put a question mark on the Earth's position in 2018 with respect to the comet's knot, since the orbital geometry between the two seemed about halfway to the storm of 1946 meteors (3,000 to 6,000 per hour). and the strong meteor explosion of 1985 (600-800 per hour) At the time, I had the good feeling that 2018 would bring another memorable draconian shower.
But this optimistic perspective would soon change.
"Drill a hole" in a possible meteor storm
A dense and concentrated meteoroid stream like the draconids has a complex structure, which was always extremely difficult to map because we could not see it. Twenty years ago, the best we could do was try to predict the activity of the meteors by determining when the Earth would cross the orbital plane of Comet GZ and hoping that everything would go well. . [Amazing Photos of the Draconid Meteor Shower]
But today, astronomers who use computer simulations regularly calculate the location in space of different dust trails and have successfully predicted the intensity and arrival of the peak of various meteor showers in less than an hour, sometimes even in a few minutes.
Unfortunately, when the meteorological experts used their most recent computer simulations to project themselves into the Draconid perspective of 2018, the news was bad.
What they discovered was a large "gap" apparently open in the channel of a very dense group of meteors from 1946 to 1959. It is expected that the Earth will cross this hole Monday night and that it will miss several hundred thousands of kilometers) on a thick cloud of dusty material that could otherwise produce a tremendous meteor storm.
It is interesting to note that the Gaia satellite of the European Space Agency, launched in December 2013 to make accurate measurements on the position and distance of stars, is located about 1.5 million kilometers from the Earth and is exactly in the expected trajectory of the dense cloud of comet debris.
Canadian astronomer Peter Brown told Space.com: "ESA will redirect its spacecraft to minimize the risk of Draconides impacts, although we hope they will see some thing – it's one of the most sensitive platforms ever put into orbit to detect the small meteoroid impacts their mission. "
The experts resonate
Although the Earth is probably missing a full meteor storm, several forecasts from leading meteorologists around the world suggest that there could still be a slight rise in modest draconid activity (although of short duration (1 to 2 hours)) appearing shortly after dark. parts of eastern North America Monday night.
Brown, who along with his wife Margaret Campbell-Brown, edits the meteorite section of the annual Observer & # 39; s Handbook of the Royal Astronomical Society of Canada (RASC, 2017), predicts a peak at 19:51. HAE (23:51 GMT) with meteor activity not exceeding a few dozen meteors per hour.
Astronomer Mikiya Sato of Japan discovered an approach of the Earth to the comet's dust trail in 1953. This trail was slightly disturbed when it approached Earth in 1985. As a result, dust should disperse somewhat, but it could still produce recognizable rates in the range of 20 to 50 meteors per centered at 20:14. EDT (00:14, 9 October GMT).
Astronomer Jérémie Vaubaillon of France noted a maximum possible at 19:31. EDT (23:31 GMT) with an hourly rate of about 15 meteors.
The Russian model Mikhail Maslov found several traces of dust, but none was close enough to cause high rates in 2018. The nearest was the trace of 1953, which had been rarefied because of previous encounters with the Earth. Nevertheless, he suggests that 10 to 15 meteors could occur at 19:34. EDT (23:34 GMT).
Will the dragon ignite in 2018?
I think it must be emphasized that with the draconids, there is always a chance of surprise. There are uncertainties about the precise locations of the dust tracks released by the Comet G-Z, which are large enough to sometimes confuse attempts to model the shower with precision. Since the orbit of the Draconid meteoroid stream expands towards Jupiter, the gravity of this planet could have upset it, preventing accurate predictions for future showers.
In October 2012, for example, observers from Eastern Europe were surprised by a brief explosion of dozens of bright meteors, while Canadian radar captured thousands of radar echoes caused by the Interaction of the Earth with a trail of dust deposited by Comet GZ in 1966. The experts did not think that something remarkable would happen, but they were wrong.
So on Monday, without sacrificing your sleep, you will have a chance to see if another surprise awaits you. So what do you have to lose? This may exceed your expectations … or you may be disappointed.
Admittedly, that does not seem very beautiful, however, anything can happen. This is only the nature of the draconids of October; you never really know
Editor's note: If you capture an amazing photo from a video of the draconian meteor shower of 2018 and want to share it with Space.com for a story or slide show, send comments and pictures to [email protected]!
Joe Rao is an instructor and guest speaker at the Hayden Planetarium in New York. He writes on astronomy for Natural History magazine, Farmers' Almanac and other publications. He is also a weather forecaster for Verizon FiOS1 News in the Lower Hudson Valley in New York. follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.
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