Some daily events in the changing sky for December 31 January 9.
Thursday, December 31
Friday, January 1
Start with Orion himself, well to the right of the Moon. In his middle, the three stars of Orion's Belt are stacked nearly vertically. The Belt points up toward orange Aldebaran amid the dim Hyades, about two fist-widths at arm's length above. Poised higher over Aldebaran is the little Pleiades cluster. In the other direction, Orion's Belt points almost straight down to bright Sirius on the rise in Canis Major, about two fists below.
Saturday, January 2
Sunday, January 3
Monday, January 4
Tuesday, January 5
Wednesday, January 6
Thursday, January 7
Friday, January 8
Saturday, January 9
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 magazine of 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 Sky Atlas 2000.0 or the smaller Pocket Sky Atlas) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion by Strong and Sinnott, the more detailed and descriptive Night Sky Observer's Guide by Kepple and Sanner, or the classic Burnham's Celestial Handbook). Read how to use them effectively.
Can a computerized telescope take their place? I don't think so not for beginners, anyway (and especially not on mounts that are less than top-quality mechanically). As Terence Dickinson and Alan Dyer say in their 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 and a curious mind." Without these, "the sky never becomes a friendly place."
More beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury and Venus are hidden in the glare of the Sun.
Mars (a bright magnitude 0.8, in Leo) rises in the east-northeast around 7 or 8 p.m. local time, far below Castor and Pollux and a bit to the left. About an hour later, dimmer Regulus rises about a fist-width beneath it. By 2 or 3 a.m. Mars and Regulus are highest in the south, now lined up horizontally.
In a telescope Mars is 13 arcseconds wide, nearly as large as it will become during this apparition. The north polar cap is in good view, bordered by a wide dark collar. Identify any other surface features you can make out by using the Mars map and observing guide in the December Sky & Telescope, page 57. Mars will pass closest to Earth on January 27th, when it will be 14.1 arcseconds wide.
Jupiter (magnitude 2.1, at the Capricornus-Aquarius border) shines brightly in the southwest in twilight, but lower after dark. It sets around 8 p.m.
Saturn (magnitude +0.9, in the head of Virgo) rises in the east around 11 or midnight and stands highest in the south before dawn. It's about 1° north of the 4th-magnitude star Eta Virginis. Saturn's rings are narrow, tilted 5° from edge-on to us, their maximum tilt until next August.
Uranus (magnitude 5.9, just south of the Circlet of Pisces) is still pretty high to Jupiter's upper left just after dark.
Neptune (magnitude 8.0, in Capricornus) lurks 2° or 3° lower right of Jupiter. To identify Uranus and Neptune with binoculars or a telescope, use our finder charts for these two planets.
Pluto is behind the glare of the Sun.
All descriptions that relate to your horizon or zenith 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.
"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 (18541912)
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