Astronomy, northern style
It's about 9 pm on a cool May evening, and some Yukon amateur astronomers are out pushing the season. Light is their enemy now and there is not a star in sight, but still they have set up an array of high-powered telescopes and cameras here at the Miles Canyon lookout.
 |
|
These three exposures show the moon entering and passing through the Earth's shadow.
(photo: Stephen Barnes, courtesy of NASA)
|
James Cackette has already been here for more than an hour, his 8-inch telescope trained on Grey Mountain. Any moment now a full lunar eclipse is supposed to come into view over the peak's southern shoulder.
But right now there is little to see but a sweeping curtain of clouds which totally covers the spot where the moon should be appearing.
"This is a hobby that takes great patience," explains Cackette, the main organizer of the Northern Deep Sky Observers Club.
Patience is probably a requirement for astronomers everywhere. Here in the North, one could also add cold-hardiness, continual optimism and a good supply of warm clothes to that list. In short, sky gazing in the Yukon is not for the faint of heart.
The group tries to hold a "star party" every Saturday night through the peak season, meaning winter, but Cackette says that they end up canceling on about three out of every five Saturdays.
Cold weather is the obvious problem, and -25 Celsius is the cutoff temperature for events. "We used to go out even at -45, but now that is harder on the body than on the equipment," he says.
But high humidity can also wreak havoc with the equipment, causing the optical systems to freeze. Also the telescopes have to be set up well ahead of time so that the mirrors have time to cool down. Otherwise condensation can make the images cloudy.
"In winter it can take two hours for them to cool down, and by that time the clouds have moved in."
Newcomers are welcome to show up at any of the gatherings and use the telescopes set up by members. "The more people who get into it, the better. And if you have a pair of eyeballs, it's free," he says.
Cackette also encourages people to use binoculars for observing the skies, and says that they are the one piece of equipment that he would never give up.
"Binocs are my favourite toys for looking at the moon. They are seriously underrated for astronomers. You get 40 percent more detail with them because you are using both eyes," he says.
Tonight he has two pairs of binoculars set up on tripods, but they are getting little use. By 9:30 pm, the clouds still show no sign of lifting and the photographers pass the time by snapping pictures of passing birds and dramatic cloud formations.
We all continue to wait because -- if the moon does appear -- it could be a dramatic coppery red. In a lunar eclipse, the moon orbits through the circular shadow cast by the Earth.
Red-orange light penetrates the earth's atmosphere more effectively than other colors, and this reddish light projects onto the moon when it's in the earth's shadow, and is reflected back towards Earth.
Cackette is using the lull in the celestial season to repair his main telescope, a 14 inch model. He knows that he will not be doing much star watching until August, when he heads south to the annual star party held on Mt. Kobau in Osoyoos, B.C.
The dry air there makes it one of the premier locations for amateur Canadian astronomers. Sky watchers there have another advantage as well; they can see more of the sky, and more of the "deep sky" targets such as galaxies, star clusters, double stars and nebulas.
But there are still plenty of prizes to be found in the northern skies. "We have the galaxies. The Virgo Super Cluster has hundreds and hundreds of galaxies. And there's the local group, Ursa Major. Those are the two main ones that we play with up here most of the time," he says.
On this evening, it looks as though the telescopes and binoculars will not get much use. By 9:55 pm, there's still no sign of a moon, coppery or otherwise.
But Cackette is not packing up just yet. "Well, officially it's not over until 10:17."
- The Northern Deep Sky Observers Club will hold its weekly "star parties" again in the fall, and newcomers are welcome. James Cackette can be contacted at ndsojcackette@gosympatico.ca.
