The Perseids are back in full force tonight. With Jupiter and if time is not covered, the fans should see twice as many meteors than usual.
The Perseids are dust from the tail of a comet called Swift-Tuttle, which passes near Earth every 133 years. The dust tail, however, encounter the Earth every August. This dust burn on re-entering the atmosphere at a speed of 60 kilometers per second. Most are the size of a grain of sand, but some are as big as a ball.
The influence of Jupiter
In November 2014, Swift-Tuttle passed close to Jupiter. The gravity of the giant planet has changed the trajectory of the tail of the comet, which passes thus 1.5 million kilometers closer to Earth. This should double the number of particles entering the Earth’s atmosphere. This Jupiter’s influence on the Perseids was felt in 1921, 1945, 1968, 1980 and 2004.
Where to look ?
According to Marc Jobin, an astronomer at the Montreal Planetarium, it is very difficult to Quebec to see the maximum number of shooting stars under international agencies astronomy, or 150 to 200 per hour. “My record, it’s been in 2007 or 2008 in the park of La Verendrye, one of the best places in Quebec, says Jobin. And I had not seen in 70 to 80 per hour. “The brightness of Montreal makes it difficult to see more than a few comets during the evening.The peak of the Perseids will be held at 20 am, but the best time to see them is after sunset the moon at midnight. Warning: after watching a light source, the eye starts from 20 to 25 minutes to get used to the dark, even away from the city.
Swift-Tuttle was discovered in 1862 independently by two American astronomers, but it had been observed in China in 69 BC. An Italian astronomer Giovanni Schiaparelli, famous for suggesting the existence of canals on Mars, was later linked to the Perseids this comet. It is the largest object to graze the Earth, less than 130 000 kilometers. Its core has a size of 26 km, comparable to the meteorite that caused the extinction of dinosaurs 65 million years here.For several months in 1992, astronomers were concerned that Swift-Tuttle will collide with the Earth in 2126, but this risk has since been revalued at 1 in 1 million.
The Perseids in history
The Perseids are so called because they come from the direction of the constellation Perseus. They are also called “tears of St. Lawrence”, the name of a Catholic martyr executed on August 10 258 by the Roman emperor Valerian, a name that dates from the Middle Ages.
Other meteor showers
The meteor showers the most visible across Canada are not the Perseids, but the Geminids in December, according to Marc Jobin, the Planetarium. By cons, this year, the Geminids are less visible because of the full moon. Quadrantids in early January, will be against by their maximum. The most visible rains in Quebec.
- Quadrantids (2-4 Jan)
- Eta Aquarids (4-6 May)
- Perseids (August 11-13)
- Orionids (20-22 October)
- Leonids (November 16-18)
- Geminids (December 12-14)