Geminid Sky Shower Strikes This Weekend
As darkness falls this weekend, look toward the heavens for a gem of a sky show from one of the year’s best meteor showers, peaking overnight on December 13 and 14.
The annual Geminid meteor shower promises colorful shooting stars and fireballs–but with the moon in the way this year, it’s all a matter of timing, say astronomers.
“The moon is a waxing gibbous around peak and will tend to wash out the fainter objects, but still, the Geminids are one of the top showers, so we can expect a pretty good show,” said Geza Gyuk, astronomer at Adler Planetarium in Chicago.
“And it only takes one spectacular meteor to make the whole shower worthwhile to watch!”
The Geminids are unusual because they’re thought to be the only annual meteor shower created not by a comet but instead by a mysterious asteroid-like object called 3200 Phaethon.
Mystery Asteroid
Discovered in 1983 by a NASA satellite, Phaethon is a three-mile-wide space rock. Its year-and-a-half-long orbit precisely matches the appearance of the Geminids, making the body a prime candidate for the source of the meteors.
More detailed recent studies, however, have shown evidence of a debris tail, and the orbit also appears to be very comet-like. The most reasonable interpretation, says Gyuk, is simply that Phaethon is a dormant or inactive comet instead of a rocky asteroid.
“After repeated close passes to the sun, the surface volatiles [frozen gases] have been baked off, leaving a crust of rock that serves to insulate the remaining ices, reducing the outgassing levels,” he said.
Here now is our guide to enjoying this cosmic spectacle: