By Peter Becker
This week be sure to watch for Comet PanSTARRS. Binoculars are recommended, to spot the comet's glow through the brightness of dusk. Look low in the west, about a half hour after sunset.
Comets brighten as they approach the Sun. They are normally very dim when discovered, before they are close enough for solar radiation to melt the ice of the comet nucleus, and the wind of solar particles to fan out the released dust and gases. What becomes visible is not the small nucleus itself, but the hazy envelope of dust and gas surrounding it, and the dimmer tail of debris that is swept behind.
Most comets never reach naked-eye visibility, but for motivated backyard telescope users, each comet is a delight. A very few reach the magnitude and size to capture public attention.
Their maximum brightness and appearance are notoriously difficult to forecast. Although this comet had potential to be very bright, it has developed to the point where it should be a good sight in binoculars.
It may be difficult to find at first, due to the twilight glow and the fact you must look only about 10 to 15 degrees above a flat horizon (10 degrees is about the width of your fist held at arm's length).
The comet will be reasonably bright through the first three weeks of March; from night to night it gradually shifts northwest and is slightly higher at the same time each night.
The comet is closest to the Sun on March 10th. Two days later, on Tuesday March 12, a very thin crescent Moon be seen due west; the comet wil1 be positioned to the left. On March 13, the Moon will be considerably higher, thicker and easier to see.
While you are at it, enjoy the beauty of the thin crescent; as the sky darkens, the earth shine becomes evident, the dim reflection of Earth shining off the darkened portion of the Moon.
You are very likely to see distant jets low in the sky after sunset. They are so far away when viewed at this angle, at first glance the jet and its contrail appears almost stationary and in fact looks something like a comet. Binoculars will immediately reveal that this is no comet, unless it is a comet with wings and jet engines. While sunlight has already left where you are situated, from the plane, the Sun still shines; the reddened sunset rays reflect brightly off the plane.
Be sure to wave.
If their seat windows are clear enough, some passengers might have a better view of the comet than you would, being far above any haze or air pollution.
Plane seats can also be great for seeing the faint band of "zodiacal light" at this time of year. The only time I have definitely seen this dim glow, was while flying home from Florida around this time of year.
Once the stars come out, you can look for the zodiac light in the western sky. If your sky is reasonably dark, you may be able to detect (from the ground) what appears as a tall, faint hazy cone of light extending up from the western horizon and tilted to the left. It follows the ecliptic, the zone in the sky where Sun, Moon and most of the planets follow. The cone is made up of dust, believed to be left over from passing comets.
New Moon is on March 10.
Send your notes to email@example.com and let me know if you see the comet or the zodiacal light.
Keep looking up!