When comet 209P/LINEAR was discovered in 2004, it passed through the inner solar system and—like all other comets—left a trail of dust particles littering its path. Indeed, it had done the same thing countless times before, and with each passage of the comet around the Sun, more and more dust particles sputtered off from the comet linger in the inner solar system. Astronomers Esko Lyytinen of Finland and Peter Jenniskens (at the time with NASA, now with the SETI Institute) predicted that the trails left behind between 1803 and 1924 have gradually drifted directly across Earth’s orbit, and this week our planet is passing through these debris streams for the first time, possibly producing a strong meteor shower on the night of May 23rd.
As the tiny particles—about the size of a grain of sand or perhaps as large as a pea—meander around the Sun, some collide with our planet. These unlucky interplanetary drifters slam into our atmosphere at speeds as great as 45 miles per second, heating up to thousands of degrees and producing a bright streak of light called a “meteor.” On any given moonless night, casual observers might see 4–6 meteors per hour. During a typical meteor shower, the count goes up to a few dozen per hour.
According to some astronomers, this new display could produce several hundred meteors per hour! They will appear to radiate from the little-known constellation Camelopardalis the Giraffe, which lies near the more familiar, W-shaped Cassiopeia the Queen in the northern sky. Since a meteor showers is named after the constellation in which its radiant (that is, the point in the sky from which meteors’ trails seem to originate) is located, this new shower could get the rather ungainly label of the Camelopardalid meteor shower. Although we could that by giving the meteors a nickname: since the Perseid shower is also known as the “Tears of St. Lawrence,” maybe the Camelopardalids could be known as the “Tears of the Giraffe” (at least it would be easier to say).
Skywatchers eager to spot this new meteor shower should be forewarned that astronomers don’t know what will happen, as is the case when trying to predict the brightness of a comet. But the circumstances look good: Camelopardalis is a circumpolar constellation, meaning that it’s visible above the northern horizon all night. Timings for this shower favor North America, with the peak expected close to midnight late on the 23rd. Coinciding with a waning crescent moon that rises around 3:00 a.m. (the wee hours of May 24th), that should give observers a few good hours between midnight and moonlight to watch for what some astronomers are hoping will be “the next big meteor shower.”
Let us know what you see. Or better yet, try out NASA’s Meteor Counter app, and help scientists understand meteor showers better! By recording the time and brightness of each meteor, you can provide NASA researchers with much-needed data.
Bing Quock is the assistant director of the Morrison Planetarium.
Image: ASA/MSFC/B. Cooke