Dim, obscure periodic comet 209P/LINEAR is about to pass close to Earth — and bring with it a trail of debris that could make for an exciting meteor shower in May, during the predawn hours of the 24th.
Most skygazers are familiar with the usual “biggies” among meteor showers like the Perseids and Geminids. But if the calculations of celestial dynamicists are correct, we’re about to experience a terrific meteor shower that virtually no one’s ever heard of: the Camelopardalids.
Meteors from the May 24th’s early-morning display can appear anywhere in the sky, but they will appear to originate from a point (called the radiant) in the constellation Camelopardalis, the Giraffe.
Don’t blame yourself for not knowing about this one — historic records show little evidence that the “Cams” have ever made an appearance before. They are bits of dust cast off from periodic comet 209P/LINEAR, an obscure, dim comet that circles the Sun every 5.1 years.
What’s got dynamicists excited, however, is that Earth might might plow right through relatively dense strands of debris shed by the comet long ago. This should create a strong burst of “shooting stars” on May 24th.
Several predictions suggest you might see anywhere from 100 to 200 meteors per hour from a dark location free of light pollution. That means you could perhaps see one or two meteors per minute. Some (but not all) dynamicists think there’s even an outside chance that the celestial spectacle could briefly become a meteor “storm,” with more than 1,000 arriving per hour! (But it’s also possible that the display might be weak, with just a few dozen meteors visible per hour even in a dark sky.)
Storm or no storm, they agree that the peak will likely occur between about 6:30 and 7:30 Universal Time on the 24th. This timing favors North Americans, though it means you’ll have to be out around 3 a.m. on the East Coast and just after midnight on the West Coast. The outburst will be brief, lasting just a few hours, though a somewhat longer duration is possible. Moonlight from a slender waning crescent won’t be a problem.
The meteors will appear all over the sky (so you’ll want to look in whatever direction gives you the darkest view.) But follow their bright paths backward, and they’ll lead you to a location in the dim constellation of Camelopardalis, the Giraffe, about 12° from Polaris. The high declination of this shower’s radiant, well above the northern horizon for most of us, is good news too.
Interestingly, in the past week there’ve been a few reports of really bright fireballs from this radiant direction. Are these early arrivals from the Camelopardalids? Maybe! They’ve certainly gotten the attention of dynamicist Esko Lyytinen. “This made me think that if the sky is clear here in Finland during the predicted shower, I will try to tune my fireball camera to observe in the daylight for a possible daylight fireball,” he says.
Discovered in 2004, Comet 209P/LINEAR passed through perihelion on May 6th and will skirt just 5 million miles (0.055 astronomical unit) from Earth on May 29th. That will be the 9th closest approach of any comet on record. But the comet itself won’t get any brighter than 11th magnitude. Besides, the meteors we’ll see are not from this pass — instead, they’ll be from perihelion passes as long ago as the late 1700s and early 1800s.
Adding to the uncertainty is that while the comet is active now, it might not have been all those years ago. “We do not know what rate to expect, because the comet was not observed in the 18th, 19th and early 20th centuries,” explains meteor specialist Peter Jenniskens (SETI Institute).
