Le monde entier est un théâtre,
et tous, hommes et femmes,
n'en sont que les acteurs.
Comme il vous plaira, Acte II, sc. 7

mardi 15 septembre 2015

Léonides et Perséides

Apparemment, le système solaire ressemble à qqch comme ça:


J'admets, ça a l'air cool comme ça. Mais vous savez ce qui l'est encore plus? Bien sûr que vous le savez : le fait que la Terre est plate, duh!


Bref, comme bien expliqué ici, la Terre subit des pluies de météorites régulièrement, chaque année, et dont les plus connues sont les Léonides (~novembre) et les Perséides (~août). Mais il y en a bien plus (désolé j'ai la flemme de traduire):

Date
Description
Duration
January 4Quadrantids: Radiant–Bootes. Very short lived shower, less that one day. Variable rate, but generally around 60 per hour. Speed 41 kps and bluish color.
January 16Delta Cancrids: Radiant–just west of Beehive. Minor shower, rate about 4 per hour. Very swift.
January 18Coma Berenicids: Radiant–near Coma star cluster. Only one or two per hour, but among fastest meteors known–65 kps.
February 26Delta Leonids: Radiant–midway in Leo’s back. Feb. 5 to Mar. 19 with peak in late Feb. 5 per hour at 24 kps.
March 16Corona-Australids: Radiant–16 hr 20 min, -48 deg. 5 to 7 per hour from Mar. 14 to Mar. 18.
March 22Camelopardalids: No definite peak, with only one per hour. Slowest meteors at 7 kps.
March 22March Geminids: Discovered in 1973 and confirmed in 1975. Rate generally about 40 per hour. Seem to be very slow meteors.
April 4Kappa Serpentids: Radiant–near Corona Borealis . 4 or 5 per hour from Apr. 1 to 7.
April 7Delta Draconids: Radiant–near Cepheus border. From Mar. 28 to Apr. 7. Slow meteors at about 5 per hour.
April 10Virginids: Radiant– near Gamma in bowl of Virgo. 20 per hour.
April 15April Fireballs: Radiant– between The Water Jar and Scutum, very erratic. From April 15 to 30 many bright bolides from Southeastern sky.
April 17Sigma Leonids: Radiant– at Leo Virgo border, actually has moved into Virgo in recent years. Weak shower of 1 to 2 per hour.
April 22Lyrids: Radiant– near Vega. 15 per hour, bright and long lasting meteors. From Comet Thatcher.
April 25Mu Virginids: Radiant–near Libra. 7 to 10 per hour of medium speed meteors.
April 28Alpha Bootids: Radiant– near Arcturus. From Apr. 14 to May 13. Slow meteors with fine trails.
May 1Phi Bootids: Radiant–near Hercules. From Apr. 16 to May 12. 6 per hour.
May 3Alpha Scorpiids: Radiant– Near Antares. From Apr. 16 to May 9.
May 4Eta Aquarids: Radiant– near Water Jar. From Apr. 21 to May 12. 21 per hour, yellow with bright trails. Comet Halley debris.
June 3Tau Herculids: Radiant–near Corona Borealis. About a month long, 15 per hour max, most quite faint.
June 5Scorpiids: Radiant–near Ophiuchus. 20 per hour with some fireballs.
June 7Arietids: About 30 per hour. Slow moving with some fireballs.
June 13Ophiuchids: Radiant– near Scorpius. Only 3 per hour but fast moving bolides are common.25 days
June 16June Lyrids: Radiant–near Vega. Another part of May Lyrid meteor stream. 15 per hour, faint blue meteors.
June 20Ophiuchids: Radiant– near Sagitarrius. Rate varies from 8 to 20, with occaisionally many more.
June 30June Draconids: Radiant–near handle of Big Dipper. Rate varies from 10 to 100 per hour. Pons-Winnecke Comet is parent.
July 28Delta Aquarids: Radiant–near Capricornus. 25 per hour, slow (24 kps) with yellow trails.40 days
July 30Capricornids: Radiant–near Aquarius. Tough to tell these from Delta Aquarids. 10 to 35 per hour with bolides.
August 10Perseids: Radiant–near Double cluster. 50 to 100 per hour, yellow with trails and bolides. The best modern dependable shower.5 days.
August 20Kappa Cygnids: Radiant–near Deneb. 12 per hour with many fireballs. Duration–15 days.
August 31Andromedids: Radiant– near Cassiopeia. Occaisionally spectacular, usually 20 per hour. Some red fireballs with trails. Biela’s Comet parent.
September 23Alpha Aurigids: Radiant– near Capella. 12 per hour, fast with trails.
October 7Piscids: Radiant–near Aries. 15 per hour at 28 kps.
October 9Draconids: Raidiant–near Hercules. Spectacular when comet Giacobinni-Zinner passes near Earth. 200 per hour when comet is close is not uncommon, 1000 per hour sometimes.
October 20Orionids: Radiant–near Taurus. 30 per hour, fast (67 kps) often in colors with long trails.8 days.
November 5Taurids: Radiant–near Pleaides. 10 per hour with many fireballs. Debris from comet Encke.45 days.
November 12Pegasids: Radiant–Near Square. from Oct. 10 to late Nov., 10 per hour, used to be spectacular.
November 17Leonids: Radiant–near Sickle. Most spectacular of modern showers. 1966 saw 500,000 per hour– 140 per second. Comet Temple–Tuttle is parent. 20 per hour between 33 year shows, fastest known at 71 kps.4 days.
December 10Monocerids: Radiant– near Gemini. 12 per hour.
December 11Sigma Hydrids: Radiant–near Head. 12 per hour, fast.
December 14Geminids: Radiant–near Castor. 60 per hour, many bright, white but few trails. Icarus, the Earth-crossing astroid seems to be the parent.6 days.
December 14Leo Minorids: 10 per hour, somewhat faint. Discovered by amateurs in 1971.
December 20Delta Arietids: 12 per hour, must view in early evening, before radiant sets.
December 22Ursids: Radiant–Little Dipper Bowl. Medium speed, 20 per hour, many with bright trails.

Question: sachant que le système solaire file comme on l'a vu au début dans l'espace intersidéral à des vitesses à décoiffer un chauve, comment se fait-il que ces pluies de météorites arrivent avec la régularité d'une horloge suisse tous les ans?!