A New Way to Look at Meteor Trails
By John Hlynialuk
Binoculars, with their narrow field of view, are not normally used to watch meteor showers. The unaided eye, which can encompass a much wider sky area is preferable since meteors appear anywhere in the sky and disappear before binoculars can be brought to bear. If you do see a meteor (“shooting star”) in the eyepiece of a telescope or in binoculars, it is always a happy accident.
The recent Perseid meteor shower offered a perfect chance for me to try something different during a shower: binocular meteor trail viewing.
Perseids tend to produce more than their share of fireballs. Some of the brighter ones sometimes leave behind a glowing trail which takes a few seconds to disappear. While most of these trails fade to invisibility in a second or two, some last longer, sometimes a minute or more. These are perfect binocular targets.
If you are quick, it is possible to see the glowing trail from a Perseid fireball at the higher magnification provided by binoculars. The trail looks a lot like a vapour trail from a jet that widens and fades in brightness over a short time.
During the Perseid shower in 1986, a very bright fireball left a trail about 20 degrees long that was visible to the eye for 15 seconds or so. With 10 power binoculars, the glowing gases were seen for several minutes! Over time, the trail distorted and twisted as the upper atmosphere winds changed its appearance. It broke up into three sections that drifted apart and spread out into faint diffuse clouds. The last glow finally disappeared about eight minutes later!
However, a lot has to go right for success in this endeavour. You need a bright Perseid with a persistent train, a quick response with a familiar set of binos and good aim. The odds are not on your side, but you will never forget the view.
I tried this on Perseid night at Starfest this year and was able to catch two persistent trains. Both lasted only a second or two to the naked eye, but took about 10 seconds to fade in binos. I surprised myself because, based on past lack of success, I thought it would be harder than that! It helps if you have a couple of friends alerting you to those bright fireballs that invariably appear behind you.
Although Perseid night is the best of the year for this, any night you are out skywatching with binoculars there could be a random bright meteor. In a group observing situation, anyone in the group can alert the others to swing their binoculars to a bright meteor trail. Meteor fact: Astronomers have determined that a typical meteor first appears around 130 kilometres up. They can penetrate another 100 kilometres to about 30 km above the Earth’s surface when they finally burn out.