Come enjoy the Academy for free this Sunday, December 11.
The New Year always begins with a light show. Tonight, the Quadrantid meteor shower reaches its peak. This happens when Earth sweeps through the dusty trail of a comet that has passed through the inner solar system: as the dust particles zip through our atmosphere, they burn up, causing brief streaks of light known as meteors.
This shower gets its name from the now-defunct constellation Quadrans Muralis, or the Wall Quadrant, before it got booted from Boötes. (The astronomer Jérôme Lalande hoped it would catch on, but no luck.) The less-than impressive ex-constellation formerly occupied a space now given over to the northern portion of Boötes the Herdsman.
Never heard of the Quadrantids? You’re not alone. Like the more spectacular Geminid shower of December, the Quadrantids are rated as a very good shower, but most folks in the Northern Hemisphere don’t take much notice. Why? Because the Quadrantids take place during the wintertime, when most people usually have something more reasonable to do than spending a cold night standing outside, gazing up at the sky. For some reason, most people prefer staying up all night for the Perseid meteor shower, which takes place in early August. Go figure.
The Quadrantid shower typically produces about 40 meteors per hour, but it often distinguishes itself with displays of hundreds of meteors during a very sharp, narrow peak of a few hours. This year, some astronomers predict that the peak will occur between 11pm PST on the 3rd and about 2am on the morning of the 4th, favoring North America. If this prediction is correct, West Coast observers should start observing around 11pm, weather permitting.
Although the brightness of the waxing gibbous Moon may interfere with observations tonight, observers may nevertheless be lucky enough to spot early "Earth grazers" before midnight. These are meteoroid particles that skim tangentially through the upper atmosphere, causing long, bright streaks that may be visible despite moonlight. The number of Earth-grazers decreases after midnight as our planet rotates into the direction from which the meteoroid particles are coming. After moonset at 3am, skywatchers still have a few hours of "dark time" to observe the year's kickoff meteor shower.
Bing Quock is the assistant director of the Morrison Planetarium.
Image by Mila Zinkova/Wikimedia