Set your alarm for 11 p.m. ET on Thursday, as that's when the Geminid meteor shower peaks. It could deliver dozens (or even hundreds) of visible meteors per hour until about 3 a.m. on December 14. Keep your eyes (and scopes) toward the constellation Gemini for the best view of the shiny shower.
What causes the Geminids? The consensus among astronomers indicates that the light show originates from the remnants of an extinct comet known as 3200 Phaethon. The unusual object 3.2 miles in diameter once contained ice and the usual components of a comet, but gradually shed many of those features due to its extremely close orbit with the sun (it gets even closer than Mercury). However, some astronomers remain on the fence about the specific details of the Geminid shower's origin.
Regardless of the origin, every year around mid-December the Earth passes through the aforementioned debris, giving us the opportunity to witness a rare event.