Geminid meteor shower 2010: Why is the Phaethon asteroid going to pieces?
Geminid meteor shower 2010 climaxes between midnight Monday and dawn Tuesday. But the spectacle also poses a question: Why is the asteroid that supplies the meteorites breaking apart?
The Geminid meteor shower for 2010 peaks overnight Monday with what promises to be a spectacular show for sky watchers who find themselves under clear, dark skies with an unobstructed view of the horizon.
By some estimates, the Geminid meteor shower – so named because they appear to the observer to be emanating from the constellation Gemini – could yield up to 120 shooting stars an hour for those watching under ideal viewing conditions between midnight and dawn Tuesday.
For astronomy buffs, the Geminids often provide the best meteor-shower show of the year. For some astronomers, however, the display and its source – an asteroid known as 3200 Phaethon – represent something of a mystery: Where did this asteroid come from and why does it appear to be shedding like a golden retriever, something asteroids generally don't do?
Phaethon is a near-Earth asteroid – an object some three miles across whose orbit around the sun each 1.4 years brings it close to Earth's orbit and to within 13 million miles of the sun, well inside Mercury's orbit.
Astronomers discovered Phaethon in 1983 using a space-based infrared telescope known as IRAS. Once researchers had calculated the asteroid's orbit, the late astronomer and comet specialist Fred Whipple noticed that its path matched that of the debris stream that generates the Geminid shower.