There is a potentially impressive meteor shower coming up later. We’ll review the circumstances behind it, where and how to view it for best results. But first we’ll look at when to observe the annual Leonid shower.
The Leonid meteor shower for 2017 will be peaking on the night of Friday, November 17. Probably more accurate to say peaking on the morning of Saturday, November 18. The meteors are expected to be more numerous between midnight and morning twilight.
The great thing about this year’s shower is it occurs on a weekend. Observers with clear skies can stay up late to watch. A second advantage is that glaring light from the moon does not interfere. A moonlit sky reduces contrast, diminishing the streaks of light from the fainter meteors. The same can be said for artificial light illuminating the sky from street lights, security and yard lights.
Although meteors are sometimes referred to as falling or shooting “stars” they are really not stars at all. Each Leonid meteor is a small granule of dust traveling through space as a “meteoroid” that glows briefly as it collides with the Earth’s protective atmosphere. Entering the atmosphere traveling at around 40 miles (approx. 70 kilometers) per second, the tiny meteoroids burn up more than 50 miles above Earth’s surface. Our atmosphere acts as a shield, protecting us as we enjoy the show from a safe distance.
The Leonid meteor shower is associated with debris left behind during subsequent passages of Comet 55P/Tempel-Tuttle. The comet orbits the sun approximately once every 33 years.
The best way to maximize the number of meteors you can expect to see during any meteor shower is to observe from a dark sky site far away as possible from interfering artificial outdoor lighting. This means avoiding the sky glow around any nearby cities. The darker the sky is at your observing site the more meteors you will see. Keep in mind predictions for meteors are only approximations and might turn be wrong either over- or under-predicting the yield. Frequently predictions fail to live up to expectations, although at times they can be exceeded. Predictions also include fainter meteors that could be difficult to see.
During an average Leonid meteor shower an observer in a dark sky location far away from artificial exterior lighting fixtures (i.e. sources of “light pollution”) may expect to see under 50 Leonid meteors per hour.
Showers occurring during returns of the comet can have increased numbers. A few years ago when living south of Sykesville I counted 138 in a two hour period. That was 2-3 years after the comet made its last pass.
It’s November, so dress warm, keep the outside lights off and just look up. The Leonids may appear anywhere in the sky, but their trails will always point back toward the head of the constellation Leo the Lion. The important thing is to be as comfortable as possible. The best equipment for meteor observing is a lawn chair with a blanket or sleeping bag and the unaided eye. You will want to have a clear view of the sky free from surrounding buildings and trees.
A meteor shower is a great event for family and friends to do together, so don’t pass up the chance.