Wednesday evening and Thursday morning (Dec. 13-14) is the peak time for one of the best meteor showers of the year – the Geminids.  The Moon is in its new phase on this Dec. 12, so it won’t interfere with viewing the shower.

While the best night is Dec. 13-14, there could be significantly more meteors in the sky than usual on the evenings and pre-dawn hours before and after too.  Meteors or “shooting stars” (which have nothing to do with stars) are pieces of cosmic dust and dirt hitting the Earth’s atmosphere at high speed and making a flash of light.  These flashes could happen anywhere in the sky, so it’s best to view the shower from a dark, wide-open place.  See the list at the end for viewing suggestions. 

The Geminid meteors are cosmic “debris” left over from a small, unusual, but regularly returning object, called Phaethon (pronounced Fay-uh-thon).  It is a small, rocky chunk which orbits the Sun in 1.4 years (not too different from the Earth’s 1-year orbit.)  During its travels, it gets close to the Sun, which heats it tremendously, loosening dirt and dust which it then leaves behind. It is this long and wide dirt and dust stream that our planet encounters every December.  

Each flash you see is a bit of its material hitting the Earth’s atmosphere and getting heated up (and heating up the air around it) as it speeds through our thick atmosphere.  Both the superheated dust and dirt and the heated air contribute to the visible light we observe.  Astronomers don’t fully understand why Phaethon sheds so much material (when other rocky objects don’t); one idea is that it may be the survivor of a collision long ago.