Plan ahead for the total eclipse of the Moon over the Americas late on the night of Sunday the 20th. The eclipsed Moon will be high in a dark sky. See Bob King's Guide to January’s Supermoon Total Lunar Eclipse, or the cover story of the January Sky & Telescope.
Friday, January 11
• As twilight fades this evening, how soon can you detect Mars glimmering above the Moon? They're about 18° apart (in early evening for North America). Mars is magnitude +0.6.
• Orion is on display in the southeast these evenings, higher every week. But when the stars come out he's still lower, and his three-star Belt is still nearly vertical. The Belt points up toward Aldebaran and, even higher, the Pleiades. Down below, the Belt points to where Sirius rises around the time twilight fades away.
Saturday, January 12
• Now Mars is only 5° or 6° to the Moon's upper right in the evening, as shown here. Mars is actually about twice as large as the Moon, but it's currently 240 times farther away.
• For the next few mornings, Venus forms a roughly equilateral triangle with Jupiter to its lower left and fainter Antares more directly below it. See the illustration here.
Sunday, January 13
• First-quarter Moon (exactly so at 1:46 a.m. on the 14th EST). In early evening the Moon is about a fist at arm's length left of Mars.
Monday, January 14
• In this very coldest time of the year, the dim Little Dipper hangs straight down from Polaris in early evening — as if, per Leslie Peltier, from a nail on the cold north wall of the sky.
The Big Dipper, meanwhile, is creeping up low in the north-northeast. Its handle is very low and its bowl is to the upper right.
And Cassiopeia, a flattened letter M, is nearly overhead in the north-northwest, just beginning to tilt.
Tuesday, January 15
• The Moon shines high due south shortly after dark. Below it by 7° (less than a fist at arm's length), can you see Alpha Ceti, magnitude 2.5? If so, can you detect the star's reddish orange tint? It's a giant of spectral type K7.
• You may know where the center of our Milky Way galaxy is: in Sagittarius by the Large Sagittarius Star Cloud. But that's for summer. How about the galactic anticenter, high in the winter evening sky? Pinpoint its location at the Taurus-Auriga border, near Beta Tauri, using binoculars and Matt Wedel's diamond-shaped asterism with his Binocular Highlight column in the January Sky & Telescope, page 43. Here, you're looking precisely outward away from the galaxy's center.
Wednesday, January 16
• After nightfall, look through the moonlight for the Pleiades above the Moon, and for Aldebaran and the dim Hyades to the Moon's left, as shown here.
Thursday, January 17
• Now Aldebaran is right of the Moon after dinnertime, as shown here.
• Algol is at minimum brightness for a couple hours centered on 6:59 p.m. EST. It takes several more hours to rebrighten. Comparison-star chart.
Friday, January 18
• Zero-magnitude Capella on high, and equally bright Rigel in Orion's foot, are at almost the same right ascension. This means they cross your sky’s meridian at almost exactly the same time: around 9 or 10 p.m. now, depending on how far east or west you live in your time zone. (Capella goes exactly through your zenith if you're at latitude 46° north: Portland, Oregon; Montreal; central France.) So, whenever Capella passes its very highest, Rigel always marks true south over your landscape, and vice versa.
And tonight, the bright Moon shines between them.
Saturday, January 19
• The Moon shines in Gemini this evening, with Castor and Pollux to its left, Betelgeuse farther to its right, and Procyon down below the Moon.
• Sirius twinkles brightly after dinnertime under Orion in the southeast. Around 8 or 9 p.m., depending on your location, Sirius shines precisely below fiery Betelgeuse in Orion's shoulder. How accurately can you time this event for your location, perhaps using the vertical edge of a building? Of the two, Sirius leads early in the evening; Betelgeuse leads later.
• Remember — plan for the total eclipse of the Moon over the Americas late tomorrow night!
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.
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.
Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, are the even larger Interstellarum atlas (stars to magnitude 9.5) and 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, or the bigger Night Sky Observer's Guide by Kepple and Sanner.
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 (meaning heavy and expensive). And 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."
This Week's Planet Roundup
Mercury is lost in the sunrise.
Venus (magnitude –4.5) and Jupiter (magnitude –1.8) rise well before the first light of dawn. They dominate the southeast as dawn begins to brighten. Venus is the upper one this week. Watch them draw together day by day. They're 9° apart on the morning of the 12th, 4° by the 19th, and they'll pass closest, 2.4° apart, on the morning of the 22nd.
And, look about 6° to Jupiter's right or lower right for orange Antares, twinkly and much fainter.
Mars (magnitude +0.6, in Pisces) shines high in the southwest at nightfall and sets around 11 p.m. In a telescope it's gibbous and disappointingly small, barely 7 arcseconds from pole to pole.
Saturn, like Mercury, is out of sight deep in the sunrise.
Uranus (magnitude 5.8, at the Aries-Pisces border) is highest in the south right after dark. It's visible in binoculars if you have a good finder chart and if you know the constellations well enough to see where to start with the chart.
Neptune (magnitude 7.9, in Aquarius) is getting low in the southwest right after dark. Finder charts.
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 or GMT) minus 5 hours.
"Rational and innocent entertainment of the highest kind."
— John Mills, 19th century Scottish manufacturer and founder of Mills Observatory, on amateur astronomy.