Wednesday, January 10, 2007
Jimmy Westlake's Celestial News column appears Tuesdays in the Steamboat Today.
Find more columns by Westlake here.
Not everything in astronomy can be predicted far in advance. A faint comet discovered last year by Australian comet-hunter Robert McNaught has brightened suddenly and dramatically as it has neared the sun.
Comet McNaught now rivals the brightest stars in the sky and might yet surpass Venus in brilliance. Unfortunately, Comet McNaught is hugging the western horizon as it zooms toward the sun, so it is visible only for a few minutes after sunset and must be viewed through the colorful twilight.
On Jan. 14, it will be less than half as far from the sun as the innermost planet, Mercury - a dangerous place for a snowball to be. In the intense solar heat, the icy material in Comet McNaught is vaporizing rapidly and forming a large, bright head and tail.
Comet McNaught will be visible to northern hemisphere observers for another week, at most. To see it, find a high observation point with a clear view of the western horizon and use binoculars to scan the sky beginning at about 5:15 p.m. Once you spot the comet with binoculars, it should be easy to see with the unaided eye. On Jan. 9 to 11, Comet McNaught will be approximately one hand-span - held at arm's length - to the lower right of Venus, the bright "evening star" visible in the west. The comet sets by 5:45 p.m., however, so the window of opportunity to view it is very narrow.
Comet Hale-Bopp - of 1997 fame - is probably the brightest comet that most people can recall seeing. Comet McNaught will undoubtedly surpass Hale-Bopp in brightness, but unlike Hale-Bopp, it's unfavorable viewing geometry means that very few people will be successful in spotting it without making a concerted effort.
For photos and updates about Comet McNaught's visibility, point your web browser to www.spaceweather.com. Then, get out the binoculars and see one of the brightest comets of our lifetime.