The Geminids peak on both Saturday and Sunday nights this weekend December 13-14. The radiant – where the meteors appear to stream from – lies near Castor and Pollux in Gemini and rises high enough by 9:30 p.m. local time to begin shower watching. Source: Stellarium
Get ready for the year’s best meteor shower. The reliable, rich and colorful Geminids will climax on not one but two nights. Even better, it all happens this weekend before midnight. No arising at 4 a.m. on a Tuesday.
A bright Geminid slices the sky in this time exposure taken on December 13, 2012. Each meteor represents a vaporized fragment of dust or rock lost by asteroid 3200 Phaethon, the Geminids’ parent. Credit: Bob King
Most sources will tell you that we’ll see up to 120 meteors per hour, but 60-80 is more realistic from light polluted location. I’ll take it. That’s plenty of meteors to take the sting out of stepping into the cold. Maximum occurs on Sunday morning at 6 a.m. but that’s near dawn and the moon will be up – not ideal conditions for viewing. That’s why Saturday and Sunday evenings are best.
The Geminids radiate from near the twin bright stars Castor and Pollux in Gemini. Most major meteor showers don’t really get going until the morning hours because their radiants either haven’t risen or are still too low before midnight. The Geminid radiant on the other hand climbs high enough by 9:30 in the evening to cast a nice spread of meteors before moonrise.
Oh yes, the moon. It rises around midnight Saturday night and 1 a.m. Monday morning. Its light will cut into meteor counts, but since Gemini’s well up in the east before moonrise, we have 2-3 hours of great meteor watching under dark skies.
See what I mean – this shower’s ideal for family viewing since you don’t have to be up too late. It’s also the richest shower of the year, having surpassed the more familiar August Perseids some years ago. Now all we have to do is hope for good weather.
Unlike most meteor showers, which originate with dust spewed by comets, the Geminids are tiny pieces of asteroid 3200 Phaethon, sometimes called a “rock comet”. Here it sprouts a tenuous tail (points to lower left) when near the Sun in this image taken by NASA’s STEREO Sun-observing spacecraft in 2012. Credit: Credit: Jewitt, Li, Agarwal /NASA/STEREO
Observing a meteor shower requires no special equipment outside of a warm coat, heavy gloves, insulated boots, electric sock warmers, hand warmers and one of those plug-in Amish fireplaces. Just kidding of course, but not about the gloves, jacket and boots! Aw, chuck it all and just watch from a hot tub.
I like to lay back in a recliner under a blanket to stay warm and comfortable. A little hot cocoa or tea doesn’t hurt either. Face east or south between 10 and midnight from a reasonably dark sky location and you’re certain to see at least a few Geminids.
The Perseids and many other meteor showers are the spawn of comets. Earth plows through the dust left by vaporizing comet ices and it burns up in the atmosphere as meteors. Every year in mid-November we travel across the orbit of Comet Temple-Tuttle and wow to the Leonids.
Italian astronomer Gianluca Masi will webcast live coverage of the Geminid meteor shower this weeked. Click image for details. Credit: Gianluca Masi
Not so with our featured shower. It and the January Quadrantids are the only major showers with asteroid parents. 3200 Phaethon, a 3.2 mile-wide asteroid that comes surprisingly close to the Sun (13 million miles) and orbits it every 1.4 years, is mama and papa to the Geminids.
Long observed to be nothing more than an inert space rock, in the late 2000s astronomers watched in amazement as Phaethon developed a short, dusty tail.
It’s thought that the intense solar heat during closest approach fractures or pulverizes rocks or it may even open up a pocket of ice long covered by debris. Perhaps Phaethon is an extinct comet or a hybrid mix of ice and rock.
I hope you have clear skies at least one night this weekend. If you do or don’t, you can always check out Italian astronomer Gianluca Masi’s Geminids webcast starting at 8 p.m. CST December 13th (2 a.m. UT Dec. 14) on his Virtual Telescope Project site.