December is a month when dedicated skywatchers have to sacrifice comfort to take in some beauty. As winter cold hits much of the Northern Hemisphere, the reliable Geminid meteor shower peaks in the middle of the month, rewarding those willing to bundle up and venture out into the night.
‘With the moon setting just before midnight, conditions should be perfect for a classic Geminids meteor shower this year,’ Slooh astronomer Paul Cox said in a statement.
But this year brings a skywatching bonus: the peak of the Geminids comes Thursday and Friday night, just as the brightest comet of the year, 46P/Wirtanen, is set to come historically close just a few nights later on Dec. 16.
This remarkable video shot by Joe Lawton of Gerald, Missouri, shows a Geminid flaming out with Wirtanen in the background:
The Geminid shower happens each year at this time, as Earth passes through the huge debris cloud left behind by the object 3200 Phaethon, an odd blue asteroid that may be an extinct comet.
‘Phaethon orbits the sun every 17 months or so, leaving a trail of debris behind it,’ Cox explains. ‘When Earth passes through the trail, the sand-grain-sized meteoroids are vaporized in our atmosphere as spectacular meteors.’
The Geminids are up there with the Perseids of August in terms of producing a nice quantity of fireballs and other bright streaks across the sky. You can expect to catch as many as 100 to 150 per hour with clear skies and limited light pollution.
To check out the show, Bill Cooke from NASA’s Meteoroid Environment Office advises urges waiting until the moon goes down at around 10:30 p.m. local time before heading outside without your cell phone, because its screen can mess up your night vision.
‘Lie flat on your back and look straight up, taking in as much sky as possible. You will soon start to see Geminid meteors. As the night progresses, the Geminid rate will increase, hitting a theoretical maximum of about 100 per hour around 2 a.m.’
For a little help spotting comet Wirtanen, NASA offers the handy skymap below to look for the glowing green ball of light, likely located a little higher in the sky than the star Aldebaran near the constellation of Taurus the bull.
Cooke suggests taking binoculars or a small telescope outside with you to try and get a better look.
If the weather doesn’t cooperate where you are, you can still get a virtual glimpse of the show via the online Slooh Observatory Thursday starting at 3 p.m. PT. Or just celebrate the 2018 Geminids with this Google doodle tracing the meteor shower’s journey from the sun.