Every year, in December, the planet Earth crosses the orbital path of an object called 3200 Phaethon, a mysterious body that is sometimes referred to as a rock comet. The debris shed by 3200 Phaethon crashes into Earth’s upper atmosphere at some 80,000 miles (130,000 km) per hour, to vaporize as colorful Geminid meteors.
This Geminids’ radiant point nearly coincides with the bright star Castor in Gemini. That’s a chance alignment, of course, as Castor lies about 52 light-years away while these meteors burn up in the upper atmosphere, some 60 miles (100 km) above Earth’s surface.
Castor is noticeably near another bright star, the golden star Pollux of Gemini. It’s fun to spot them, but you don’t need to find a meteor shower’s radiant point to see these meteors.
Instead, meteors in annual showers appear in all parts of the sky. It’s even possible to have your back to the constellation Gemini and see a Geminid meteor fly by.
In 2019, the peak of the Geminid meteor shower is coming up on the mornings of December 13 and 14.
Earthgrazers possible at early evening. You’ll likely see the most meteors at a time of night centered around 2 am. You won’t see as many Geminid meteors in early evening, when the constellation Gemini sits close to the eastern horizon.
But the evening hours are the best time to try to catch an earthgrazer meteor.
An earthgrazer is a slow-moving, long-lasting meteor that travels horizontally across the sky.
Earthgrazers are rarely seen but prove to be especially memorable, if you should be lucky enough to catch one.
Be sure to give yourself at least an hour of observing time. It takes about 20 minutes for your eyes to adapt to the dark.
Source: Earth Sky