MorningSong
9th December 2010, 14:47
Before everyone starts exclaiming "the sky is falling", I thought I'd bring it to everyone's attention that we will be witnessing the Geminid Meteor showers for the next few weeks. Heads up!
From Spaceweather.com Dec 7th:
GEMINID METEORS DEFY EXPLANATION: The annual Geminid meteor shower peaks this year on Dec. 13th and 14th. Researchers don't fully understand the Geminids, and new measurements, they say, make it more mysterious than ever. Get the full story from Science@NASA.
And the story at NASA is interesting, too.
http://science.nasa.gov/science-news/science-at-nasa/2010/06dec_geminids/
Geminid Meteor Shower Defies Explanation
Dec. 6, 2010: The Geminid meteor shower, which peaks this year on Dec. 13th and 14th, is the most intense meteor shower of the year. It lasts for days, is rich in fireballs, and can be seen from almost any point on Earth.
It's also NASA astronomer Bill Cooke's favorite meteor shower—but not for any of the reasons listed above.
"The Geminids are my favorite," he explains, "because they defy explanation."
Most meteor showers come from comets, which spew ample meteoroids for a night of 'shooting stars.' The Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris—not nearly enough to explain the Geminids.
"Of all the debris streams Earth passes through every year, the Geminids' is by far the most massive," says Cooke. "When we add up the amount of dust in the Geminid stream, it outweighs other streams by factors of 5 to 500."
This makes the Geminids the 900-lb gorilla of meteor showers. Yet 3200 Phaethon is more of a 98-lb weakling.
3200 Phaethon was discovered in 1983 by NASA's IRAS satellite and promptly classified as an asteroid. What else could it be? It did not have a tail; its orbit intersected the main asteroid belt; and its colors strongly resembled that of other asteroids. Indeed, 3200 Phaethon resembles main belt asteroid Pallas so much, it might be a 5-kilometer chip off that 544 km block.
"If 3200 Phaethon broke apart from asteroid Pallas, as some researchers believe, then Geminid meteoroids might be debris from the breakup," speculates Cooke. "But that doesn't agree with other things we know."
Researchers have looked carefully at the orbits of Geminid meteoroids and concluded that they were ejected from 3200 Phaethon when Phaethon was close to the sun—not when it was out in the asteroid belt breaking up with Pallas. The eccentric orbit of 3200 Phaethon brings it well inside the orbit of Mercury every 1.4 years. The rocky body thus receives a regular blast of solar heating that might boil jets of dust into the Geminid stream.
Could this be the answer? ........
From Spaceweather.com Dec 7th:
GEMINID METEORS DEFY EXPLANATION: The annual Geminid meteor shower peaks this year on Dec. 13th and 14th. Researchers don't fully understand the Geminids, and new measurements, they say, make it more mysterious than ever. Get the full story from Science@NASA.
And the story at NASA is interesting, too.
http://science.nasa.gov/science-news/science-at-nasa/2010/06dec_geminids/
Geminid Meteor Shower Defies Explanation
Dec. 6, 2010: The Geminid meteor shower, which peaks this year on Dec. 13th and 14th, is the most intense meteor shower of the year. It lasts for days, is rich in fireballs, and can be seen from almost any point on Earth.
It's also NASA astronomer Bill Cooke's favorite meteor shower—but not for any of the reasons listed above.
"The Geminids are my favorite," he explains, "because they defy explanation."
Most meteor showers come from comets, which spew ample meteoroids for a night of 'shooting stars.' The Geminids are different. The parent is not a comet but a weird rocky object named 3200 Phaethon that sheds very little dusty debris—not nearly enough to explain the Geminids.
"Of all the debris streams Earth passes through every year, the Geminids' is by far the most massive," says Cooke. "When we add up the amount of dust in the Geminid stream, it outweighs other streams by factors of 5 to 500."
This makes the Geminids the 900-lb gorilla of meteor showers. Yet 3200 Phaethon is more of a 98-lb weakling.
3200 Phaethon was discovered in 1983 by NASA's IRAS satellite and promptly classified as an asteroid. What else could it be? It did not have a tail; its orbit intersected the main asteroid belt; and its colors strongly resembled that of other asteroids. Indeed, 3200 Phaethon resembles main belt asteroid Pallas so much, it might be a 5-kilometer chip off that 544 km block.
"If 3200 Phaethon broke apart from asteroid Pallas, as some researchers believe, then Geminid meteoroids might be debris from the breakup," speculates Cooke. "But that doesn't agree with other things we know."
Researchers have looked carefully at the orbits of Geminid meteoroids and concluded that they were ejected from 3200 Phaethon when Phaethon was close to the sun—not when it was out in the asteroid belt breaking up with Pallas. The eccentric orbit of 3200 Phaethon brings it well inside the orbit of Mercury every 1.4 years. The rocky body thus receives a regular blast of solar heating that might boil jets of dust into the Geminid stream.
Could this be the answer? ........