Alaska Not Well Suited for Stargazing
Anyone who has been trying to locate Halley's comet for the last month or so has become familiar with a fact of life that skywatchers have known for a long time: the skies above Alaskans are usually hazy.
One reason for this is that most population centers in Alaska lie at low elevations beneath practically the entire blurry blanket of the atmosphere. Fairbanks is at an elevation of only 400 to 500 feet. The coastal cities, Anchorage included, are in even worse shape. They lie at lower elevations still, and viewers must cope with the additional screening effect of salty ocean haze as well.
When the transparency of the atmosphere is as poor as it usually is around the Alaskan population centers, even a small additional loss may be enough to entirely mask very faint objects--such as Halley's comet.
One such loss is caused by airglow, a phenomenon that is not peculiar to Alaska, but which may play a role anywhere that viewing conditions are marginal. Airglow is light emitted by gas molecules in the upper atmosphere in a manner similar to that which produces the aurora. Unlike the aurora, however, it is not structured by the earth's magnetic field lines, but is scattered more or less uniformly over the sky. Although it is not particularly bothersome in viewing point sources of light such as stars, it can effectively screen "fuzzy" features such as comets.
Airglow is extremely feeble, and the illumination it gives to the ground can be compared with the light from a candle at a height of 100 yards. That it may play a role in masking Halley's Comet gives an indication of just how faint the comet is this time around.
Serious astronomers could point out yet another problem for stargazers in the far north: you get to see only a portion of the sky. At the equator, the entire sky will turn above you over the course of a season. Near the poles, you miss everything south of a horizontal plane passing through your latitude. So even discounting the fact that when it's dark outside, it's usually cold, and when it's warm, it's usually light, the northern latitudes are not well situated for an astronomical observatory.
However, imperfect is not the same as impossible. When the original Geophysical Institute building was completed on the University of Alaska's Fairbanks campus in 1950, its most distinguishing feature was the silver dome on top which housed a 12-inch reflecting telescope--a Mt. Palomar in miniature. The building with its dome is still a prominent landmark on the Fairbanks campus, but the telescope was dismantled many years ago. Optical astronomy was never intended to be a major research objective at the Geophysical Institute which was--and is--dedicated to research into geophysical phenomena at high latitudes. But the old building and its dome still provide a poignant reminder to the old school of stargazers that there is nothing on a frosty night like a good telescope and a hot thermos of coffee.
