Comet PanSTARRS update: The incoming comet that we hoped would make a fine showing in March has been weakening. It may not even reach naked-eye visibility, what with its low altitude in the evening twilight. Follow our updates at SkyandTelescope.com/panstarrs.
Friday, February 8
Saturday, February 9
Sunday, February 10
Monday, February 11
Tuesday, February 12
Wednesday, February 13
Thursday, February 14
Friday, February 15
By the time it's visible in Western Europe it will be a little fainter, and by its visibility in North America it will be down to 11th to 13th magnitude, receding into the distance near the Little Dipper. See our article Asteroid 2012 DA14 to Zip Past Earth, with detailed telescopic finding instructions.
Saturday, February 16
Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope effectively.
You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.
Can a computerized telescope replace charts? Not for beginners, I don't think, and certainly not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability). As Terence Dickinson and Alan Dyer say in their invaluable Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."
This Week's Planet Roundup
Mercury (magnitude –1) is having an excellent apparition in the evening twilight. Look for it low in the west-southwest as the sky darkens. No other point in the area is nearly so bright. See Mercury in February 2013.
Right there too is Mars, much fainter. They're less than 1° apart on Friday the 8th; after that Mars moves lower each day and becomes harder to spot.
Venus (magnitude –3.9) is buried deep in the glow of sunrise.
Mars (magnitude +1.2) is becoming a real challenge as it sinks lower low into the sunset. Brighter Mercury is your marker for finding it; as shown here.
Mars is currently on the far side of the Sun from us, but Mercury is swinging around to the Sun's near side as shown by its growing size and diminishing phase.
Jupiter (magnitude –2.4, in Taurus) dominates the high south in early evening and the southwest later. To its left is orange Aldebaran; to its right are the Pleiades. This whole group sets around 2 a.m.
In a telescope, Jupiter is shrinking as Earth pulls farther ahead of it in our faster orbit around the Sun. This week it shrinks from 42 to 41 arcseconds wide.
Saturn (magnitude +0.5, in Libra) rises in the east-southeast around midnight, well to the lower left of Spica. By the beginning of dawn Saturn is highest in the south — more or less between Spica, far to its right, and Antares farther to its lower left.
Uranus (magnitude 5.9, in Pisces) is getting low in the west after dusk.
Neptune is lost in the glare of the Sun.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Standard Time (EST) equals Universal Time (also known as UT, UTC, or GMT) minus 5 hours.
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