Friday, January 10
Saturday, January 11
Sunday, January 12
Monday, January 13
Tuesday, January 14
Wednesday, January 15
Thursday, January 16
Friday, January 17
Saturday, January 18
Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby. 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 once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.
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 not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means heavy and expensive). 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
The Sun: A big active sunspot region, AR 1944, is visible to the unaided eye through a safe solar filter (or a #14 rectangular arc-welder's filter) for the first few days this week. It rotates closer toward the Sun's celestial western limb each day.
Mercury and Venus are in hidden the glare of the Sun. Venus passes through inferior conjunction, 5° north of the Sun, on January 11th.
Mars (magnitude +0.7, in Virgo) rises around midnight. It's highest in the south before the first light of dawn, with Spica shining to its lower left. In a telescope Mars is still small, about 7 arcseconds wide.
Jupiter (magnitude –2.7, in central Gemini) is just past its January 5th opposition. It glares low in the east as twilight fades, then rises higher in the east all evening — with Castor to its left, Pollux to its lower left, and fainter Gamma Geminorum to its right. It blazes highest in the middle of the night and low in the west at the beginning of dawn.
Saturn (magnitude +0.6, in Libra) is well up in the southeast as dawn begins to brighten. Look for it far to the lower left of Mars and Spica, and even farther below brighter Arcturus.
Uranus (magnitude 5.8, in Pisces) is still high in the southwest right after dark. Finder chart.
Neptune (magnitude 7.9, in Aquarius) is getting low in the west-southwest after dark.
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) is Universal Time (UT, UTC, or GMT) minus 5 hours.
"Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house."
— Henri Poincaré (1854–1912)
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