Every year, our planet travels 940 million kilometers in its orbit around the Sun. Over the past years, decades and centuries, comets and asteroids go through the same region of our Solar System. They leave a trail of debris in orbit around the Sun. Once in a year, the planet Earth will pass through that debris stream, creating a meteor shower.
The most spectacular ones happen in August (the Perseids), in December (the Geminids). And occasionally in November (when the Leonids are favorable). What you see varies from year to year. But in this year, the Geminids just might be the most spectacular treat which you have ever seen.
Here’s the story:
It will all start with either a comet or asteroid that gets hurled into the inner Solar System. It is close enough to the Sun to sprout a tail. Don’t be fooled with a common misconception: the tails themselves are not what give rise to meteor showers at all.
Those little dust grains — which are the particles between the major fragments, will wind up getting stretched out over the elliptical orbit of the comet over time. In such rare occasions where the orbital path of such a comet or asteroid will cross the orbit of the Earth, the particles will collide with our upper atmosphere.
There are three things which make a shower spectacular from our point of view, and they are:
– How frequent the meteors are
– How bright are those meteors,
– And the last one, how visible the meteors are, which actually depends on how dark the sky is.
The difference between a dark sky and an urban and light polluted sky is tremendous. Those meteors which are the brightest and most infrequent can still be seen from a badly polluted sky. But they will not appear very spectacular. Also, a very dark sky can result in seen ten times as many meteors, with the brighter one looking much more spectacular of the others.
How to find a dark-sky location near you?
If you are in North America, download an overlay for Google Earth or using this free online tool. Where it shows green or better (blue or grey is best) is where you’ll want to be for meteor watching.
In 2018, at the peak of the Geminids, our moon will be a waning crescent, which will not even rise until well after midnight. Even when it will, it will be thin enough, as well as far enough away from the origin of the Geminids, and you’ll still have a spectacular show. If the sky is dark and cloudless, you may have the ability to see about two or three meteors per minute. This year, you will not want to miss this opportunity!
Even when you do not see one, spending time together under a dark sky will give you the appreciation unlike any other. Find the constellation of Orion and trace the bright blue star (Rigel) to the bright red star (Betelgeuse). After that keep going until you are just above the bright twin stars, called Castor and Pollux.
This is actually the radiant or the point from which every meteor will emerge. Every meteor shower has such a point, and this one is called Geminids. The shining will happen in the constellation of Gemini, the twins, named for the twins stars Castor and Pollux.
The Geminids are supposed to peak at about 140 meteors – per – hour right after midnight. They might be more numerous but less bright than the Perseids. It is because the particles are moving just a little bit slower. If you have clear and dark skies, you’ll get to know them in this last month of the year. It is natural, as well as reward wonder unlike any other.