Sky at a Glance | January 8th, 2010

Some daily events in the changing sky for January 7 – 16.

Thursday, January 7

  • Last-quarter Moon (exact at 5:39 a.m. EST).

    Friday, January 8

  • If you want to observe the deep-sky depths of Orion at their highest and best — that is, through the least atmosphere and light pollution — you now have to wait up only until about 10 p.m. for Orion to reach its peak altitude in the south. A month from now it'll be there by 8 p.m.

    Meetup with Antares
    Early risers can watch the waning Moon pass Antares in early dawn. These scenes are drawn for latitude 40° north, longitude 90° west, near the middle of North America (not far from Peoria, Illinois, which gave rise to the phrase "Will it play in Peoria?"). European skywatchers: move each Moon symbol a quarter of the way toward the one for the previous date. For clarity, the Moon is always shown here three times its actual size.

    Saturday, January 9

  • This is the coldest time of the year — when the dim Little Dipper hangs straight down from Polaris after dinnertime, as if (per Leslie Peltier) from a nail on the north wall of the sky. This is also when the Northern Cross of Cygnus stands planted upright on the cold northwest horizon (as seen from mid-northern latitudes).

    Sunday, January 10

  • If you're up before dawn Monday morning, look for Antares very close to the waning crescent Moon low in the southeast, roughly as shown at right.

    In northeasternmost North America (northeast of a line from Boston through the Adirondacks past Ottawa to northern Ontario) the Moon occults Antares, more or less around the time of sunrise. For this you'll need a telescope. See our article and map.

    The grazing-occultation line goes right through downtown Boston. There, "the Sun will be about 3° above the horizon and Antares will be about 19° up," writes David Dunham of the International Occultation Timing Association. "Observers in eastern Massachusetts should set up their telescopes and start observing Antares a half hour before sunrise, then track the star to the event, since Antares and the thin crescent Moon will be hard to find after sunrise."

    Monday, January 11

  • If you're up at dawn Tuesday, spot the thin crescent Moon low in the southeast. Well to its left, look for Mercury. Binoculars help.

  • Venus is in superior conjunction with the Sun.

    This one could be tough
    As dawn grows bright Wednesday morning, use binoculars to look for Mercury upper left of the thin waning Moon.

    Tuesday, January 12

  • A dawn challenge: half an hour before sunrise Wednesday morning, look low for Mercury and the very thin sliver of a Moon, as shown here. You can always find your local sunrise time, and much else, once you put your location into our online almanac. (Make sure the Daylight Saving Time box is unchecked.)

    Wednesday, January 13

  • Late tonight and tomorrow night, once Saturn climbs reasonably high in the southeast, a telescope will show Saturn's largest satellite, Titan, about four ring-lengths to the planet's west.

    Thursday, January 14

  • The red long-period variable star R Leporis, known as Hind's Crimson Star or the Rabbit's Ruby, should be at maximum light this week, about magnitude 6.8. It's not far from Rigel; see the photo, chart, and article in the January Sky & Telescope, page 61. R Lep gets its unusually deep color from carbon in its atmosphere as molecular C2 gas, which acts as a red filter.

    Friday, January 15

  • An annular eclipse of the Sun occurs for parts of Africa, the Indian Ocean, southernmost India, northern Sri Lanka, Burma, and China. A partial eclipse occurs for most of the rest of the Eastern Hemisphere. See zoomable map of the zone of annularity, and other information on the rest of the eclipse. Seen from its center point in the Indian Ocean, this is the longest annular eclipse until the year 3043.

  • The eclipse, of course, corresponds with this month's New Moon (which for the center of the Earth occurs at exactly 2:11 a.m. on this date Eastern Standard Time).

    With Jupiter lighting the way, watch for this month's return of the waxing crescent Moon.

    Saturday, January 16

  • As twilight fades, look for the thin waxing crescent Moon low in the west-southwest far to the lower right of Jupiter, as shown at lower right here.


    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 emerges low in the dawn late this week. Look for it very low in the southeast. Binoculars help. Next week it'll be easier.

    Venus is hidden behind the glare of the Sun.

    Mars, shining fiery bright at magnitude –1.0, now rises in the east-northeast as early as 7 p.m. local time. It's at the Leo-Cancer border; watch for it 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 a.m. Mars is at its highest due south.

    Dark Syrtis Major was almost dead center on Mars when Ian Sharp in Britain took this image at 0:54 UT January 4, 2010. The North Polar Cap is huge and obvious. The slightly bright region on the southern limb (top) is the dusty Hellas basin. The central meridian longitude was 280°. South is up.


    Stacked-video images like this will generally show much more detail on a planet than can be seen by eye even through the same telescope.


    In a telescope Mars is 13.5 arcseconds wide, nearly as large as it will become during this apparition. The big, white north polar cap is in fine view, as seen here, bordered by a very wide dark zone. Identify other surface features that you can make out 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 in the southwest in twilight and sinks lower as night comes on. It sets around 8 p.m. local time.

    Saturn (magnitude +0.9, in Virgo) rises in the east around 11 p.m. and stands highest in the south before the first light of dawn. In earliest dawn, notice the huge, horizontal line of Pollux, Mars, Regulus, Saturn, and Spica running all the way from west-northwest to south. In a telescope Saturn's rings are 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 in view right after dark well to the upper left of Jupiter. Use our finder chart.

    Neptune (magnitude 8.0, in Capricornus) is lower right of Jupiter, sinking away into the twilight.

    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, World Time, or GMT) minus 5 hours.

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