This week is a great time to catch one of the best displays of meteors of the year, as the Geminid Meteor Shower reaches its peak the night of December 13-14. Don’t let the cold night keep you from watching even a few minutes. Bundle up as needed, and take in the celestial show.
Geminids are famous for meteors that are both bright and numerous. Under excellent conditions, 100 to 120 an hour might be observed- averaging two a minute.
The radiant of the shower is in the constellation Gemini the Twins (close to the bright star Castor). Gemini’s stars, located near Orion, are already rising in the east when darkness falls. This is especially nice, allowing a better chance to see the meteor shower in the evening hours.
One still hears the old name, “shooting stars” or “falling stars.” They are certainly not stars. If they were, our night sky would have been empty of visible stars long, long ago! Actually, meteors are cosmic visitors that interface with the Earth. Most are tiny bit of rock, like sand particles, coursing through space; they remain undetectable to even the largest telescope before being pulled by Earth’s gravitation into the atmosphere. These grains quickly vaporize as they heat up, hurtling at great speed. Light is given off when they are about 60 to 30 miles up. Most are completely vaporized high in the atmosphere. A few larger ones land, and are known as meteorites.
There are random meteors every hour of the night, coming from any direction. Most arrive in vast streams, the left over debris of comets. We refer to them as meteor showers. A few showers, like the Geminids, are associated with crumbs from asteroids. The Geminid particles have been linked to asteroid 3200 Phaethon, which circles the Sun every 1.4 years.
Meteor streams are spread along an orbit around the Sun; the Earth, in its path, intersects some of these. There must be many more meteor streams that entirely miss the Earth. They appear to radiate from a specific area of the sky, and the constellation where the radiant point is located, gives its name to the shower.
In most cases, the Earth’s advancing side collides with the meteor stream head-on. As our Earth spins and takes us around past midnight, we are on the side facing ahead in our own orbit. The shower’s radiant- and its associated constellation, are both above the horizon in the night sky of early morning as our planet plows into the coming meteors.
In the case of the Geminids, the constellation is already up in the sky and stays in the sky all through the mid-December night. When Gemini- and the shower’s radiant are high in the night sky- late evening to early morning - you can expect to see the most meteors.
Look anywhere in the sky for them. No telescope or binoculars are needed; just enjoy with your eyes alone. See how many you can count. Give some time to let your eyes adjust to the darkness and look towards the widest open area of sky you have. Try and avoid street or neighborhood lights. It’s easier on your neck if you lay back in a lawn chair- yes, it’s nearly winter but some of us might still have our lawn furniture out anyway! For an extended watch, A sleeping bag and heating packets used by hunters are very helpful.
Last quarter Moon is on December 10, and New Moon is December 18. Between these dates the Moon is a diminishing (waning) crescent, rising after midnight and not significantly brightening the sky.
If you are looking in the hour before sunrise, look low in the southeast for the bright planet Jupiter.
Keep looking up!
— Peter Becker is Managing Editor at The News Eagle in Hawley, PA. Notes are welcome at firstname.lastname@example.org. Please mention in what newspaper or web site you read this column.