An hour before sunrise on Saturday, look for Saturn high in SSW, and Mercury very low in ESE. Within 15 minutes, using binoculars, try for faint Mars rising 6° below Mercury. On each successive morning, Mars appears a little higher, and Mercury a little lower, as the two planets close in on each other. By the middle of next week, bright Jupiter appears to their lower left. On Sunday December 10, the three planets will form a very compact triplet just one degree across. We will describe changes in their arrangement as it appears daily in morning twilight in the days preceding and following their tightest gathering.

Only one naked-eye planet, Saturn, is now currently visible in a dark sky. It passes high in S not long before morning twilight begins. Two others, bright Mercury and faint Mars, rise in ESE in morning twilight and in a few days, another, Jupiter, will join them. Just one naked-eye planet, Venus, is visible in the early evening. But you must look very soon after sunset and have an unobstructed view toward SW with very clear skies. Ten minutes after sunset, Venus is very low in SW. Binoculars are a big help for finding Venus in early December, but by month's end it will set over an hour after the Sun and be easily seen with unaided eye.

As soon as the evening sky darkens enough to see some stars, turn binoculars or a telescope toward the Moon and look for stars of the Pleiades cluster nearby. From East Lansing MI, the 3rd-mag. star Alcyone, brightest member of the cluster, is covered by the Moon from 9:20 p.m. until 10:12 p.m. Times for other stars and for other cities, with maps of visibility, are available at http://www.lunar-occultations.com/iota. The Moon is just one day short of Full, so a telescope is needed to see these events. The disappearances, at the Moon's leading dark edge, are easier to observe.

December's Full Moon rises well north of east over half an hour before sunset. As the sky darkens, notice the reddish star Aldebaran, eye of Taurus the Bull, about 10° to the Moon's lower right, and Elnath, tip of the Bull's northern horn, about the same distance to Moon's lower left. An hour before sunrise on Tuesday, Moon is in WNW, with Elnath a few degrees upper left. At the same time look very low in ESE for Mercury, and for faint Mars rising within 4° below. In another 15 minutes, watch for Jupiter rising 3° lower left of Mars.

This month's northernmost Moon rises well N of E not long after sunset, and reaches its highest not far south of overhead over 8 hours later from northern U.S. The Moon sets well N of W a couple of hours after sunrise on Wednesday.

Venus is 10° upper left of the setting Sun today, so as soon as the Sun's disk drops below the horizon, use binoculars to search for Venus. The Moon rises well north of east about 1 hour 20 minutes after sunset. Three hours after sunset, look for Pollux and Castor, the Gemini Twins, 4.5° apart and to Moon's lower left. By about an hour before sunup on Thursday, Moon is nearly halfway from horizon to overhead in the west, and within 8° below the Twins. An hour before sunrise on Thursday, Mercury is very low in ESE, with faint Mars 2.2° below. In 15 minutes, Jupiter is 2.1° lower left of Mars and 4° lower left of Mercury. The three planets fit within a binocular field no more than 5° across Dec. 7-14.

Emerging in morning twilight, Jupiter is becoming visible with unaided eye. Best viewing time on Friday begins about one hour before sunrise, when the planet is just rising in ESE. Look 2.8° lower left of Mercury. Binoculars show faint Mars 1.7° lower right of Mercury and 1.7° upper right of Jupiter. Look also for the 2.6-mag. star Beta Scorpii 1/3° left or upper left of Jupiter on Fri. and Sat. mornings.

Best chance to see the shrinking trio of planets on Saturday begins one hour before sunup, when Jupiter, the lowest and brightest member, is very low in ESE. Mercury is within 1.5° to Jupiter's upper right, while faint Mars is 1.1° lower right of Mercury and 1.3° upper right of Jupiter. Saturn is high in SW, 13° to Moon's upper left.

Tonight's waning gibbous Moon rises over 20° north of east at 9:53 p.m. (for East Lansing). At 11 p.m. find Saturn within 3° to Moon's lower right, and Regulus, heart of Leo, 5° below Saturn. The Moon's southern edge passes closely north of Saturn shortly before dawn on Sunday.

The most compact gathering of three naked-eye planets between 1925 and 2053 will take place Sunday morning December 10, with prime viewing beginning one hour before sunrise. Jupiter, the brightest and still the lowest member of the trio, has already risen above the ESE horizon. Mercury appears just 0.3° above Jupiter, while faint Mars appears just one degree to their right. Saturn and the Moon are still close together, high in SW.

If you missed this morning's most compact trio of planets, you still can get a pretty view on Monday. Best viewing time begins an hour before sunrise, when Jupiter, the brightest and now the highest member, is very low in ESE. Mars is 0.8 degree (the closest it gets) to Jupiter's lower right, and sinking Mercury is 1.1° to Jupiter's lower left. Saturn is high in SW to WSW, 13° to Moon's lower right. Regulus is 5° to Saturn's upper left. Four planets and the Moon span 100°.

Best viewing time for the compact trio of planets on Tuesday begins an hour before sunrise. Jupiter is very low in ESE, with faint Mars 0.9° lower right, and Mercury rising 2.3° lower left. The Last Quarter Moon, half full and 90° (one-quarter circle) west of the Sun, is then high in S. Binoculars give wonderful views of lunar surface features.

An hour before sunup on Wednesday morning, low in SE, find faint Mars 1.2° below bright Jupiter. But Mercury, getting lower each morning, is just rising. Wait 10 or 15 minutes to spot Mercury 3.6° lower left of Jupiter.

Tonight's peak of the Geminid meteor shower is best observed from late evening until first light of dawn. About 45 minutes before sunup on Thursday, faint Mars is 1.6° below Jupiter, and Mercury is 5° to Jupiter's lower left.

One hour before sunrise on Friday, a crescent Moon is in SE with Spica closely above. Jupiter is low in ESE with Mars 2° lower left. As twilight brightens, watch for Mercury rising 6° to Jupiter's lower left.

One hour before sunrise on Saturday, look for four solar system bodies: Saturn high in WSW, 5° lower right of Regulus; Moon in SE; and Jupiter very low in ESE with Mars 2.5° below. Jupiter-Saturn, now 100° apart, will appear 180° apart on three occasions in 2010-2011. For most of those two years it will be impossible to observe both in the sky at the same time.

On Sunday one hour before sunrise (or at 7:03 a.m. in East Lansing, MI), find the crescent Moon in SE with Jupiter about 16° to its lower left, and faint Mars 3° below and a little left of Jupiter. In another 15-20 minutes, look for Antares 7° to Jupiter's lower right, and for Mercury rising 9° to Jupiter's lower left.

On Monday one hour before sunrise, look low in ESE to SE for the last thin old crescent Moon with Jupiter 6° to its upper left. Faint Mars is 3.5° to Jupiter's lower left. In the next 15 minutes, watch for Antares rising 4.5° to Mars' lower right.

On Tuesday one hour before sunrise, Mars is 4° lower left of Jupiter. (Each day they are half a degree farther apart.) On Tuesday and Wednesday watch for the rising of Antares 4.4° lower right of Mars. Mars passes this star at intervals of just under two years. On the next occasions, in Nov. 2008 and Nov. 2010, the conjunction will be impossible or difficult to observe in the solar glare. The next easy chance to see Mars and Antares in conjunction will be on the evening of Oct. 20, 2012.

One hour before sunrise on Wednesday, three visible morning planets span 105°: Saturn high in WSW, Jupiter low in ESE, and Mars 4.5° to Jupiter's lower left. Note Antares 4.4° to Mars' lower right. Mercury has moved to within 10° of the Sun.

New Moon occurs this morning at 9:01 a.m. EST and can't be seen today as it appears too close to the Sun.

Winter begins at 7:22 p.m. EST. At today's southernmost sunset (5:07 p.m. in East Lansing), the young crescent Moon is 17° upper left of the Sun and very low in SW and 4° lower left of Venus. Don't wait long after the Sun goes below the horizon to start looking for Moon and Venus. Binoculars help locate them in a bright sky.

Today's 2-1/3-day-old crescent Moon is 29° upper left of the setting Sun and 15-16° upper left of Venus. On Saturday and Sunday an hour before sunrise, look low in ESE to SE for an isosceles triangle with Jupiter at the apex, 6° above Mars and Antares, which are now 5° apart. Compare brightness of Mars and its "rival" Antares.

Today the Moon is 42° upper left of the setting Sun. Look for Venus 14° upper left of Sun and 28° lower right of Moon. Better look early to catch Venus!

Half an hour after sunset, find crescent Moon high in SSW and Venus low in SW to WSW, 42° to Moon's lower right. As sky darkens, find first-mag. Fomalhaut, mouth of the Southern Fish, 20° to Moon's lower left. At 10:30 p.m., low in eastern sky, find Saturn with Regulus 5° below. An hour before sunrise on Christmas morning, Saturn-Regulus are high in WSW. Jupiter is then low in ESE to SE, with Antares 6° lower right, Mars 7° lower left. Mars-Antares are still within 6° apart. Look daily at same stage of twilight, and you'll notice all three bodies are climbing higher each morning. But Mars will remain low in coming months, because of its rapid eastward motion against the stars.

At nightfall (about 1½ hours after sunset) find the crescent Moon, one-third full, well up in SSW to SW. Binoculars show a 4th-mag. star, Lambda in Aquarius, close to Moon's right, and 6th-mag. Uranus 0.5° below Lambda and slightly left.

About an hour after sunset, low in E to ESE in deepening twilight, find Orion's two brightest stars, reddish Betelgeuse and blue-white Rigel. Look midway between them for a vertical line of three stars marking the Hunter's belt. Poet Robert Frost aptly described the scene in the opening lines of "The Star Splitter":

You know Orion always comes up sideways.
Throwing a leg up over our fence of mountains,...

About 2½ hours after sunset, look ESE for the rising of Sirius, the "Dog Star", our brightest nighttime star. Locate this twinkling blue-white marvel by following Orion's belt down toward the horizon.

Once Sirius has risen, look for the nearly equilateral "Winter Triangle", comprised of Orion's shoulder Betelgeuse; Sirius; and Procyon, 26° to the left of Sirius and a little higher.

After nightfall, follow Orion's belt 22° upward and bend slightly north to find Aldebaran, eye of Taurus the Bull. About midway between Orion's belt and the North Star, find Capella, the Mother Goat star. Some 34° left of Betelgeuse and 30 to 34° below Capella, find Castor and Pollux, the Gemini Twins.

At nightfall, the Pleiades star cluster is some 6° east (lower left) of the Moon. By 3 hours before sunrise on Sunday, the Moon has crept much closer to the cluster, but is about to set in WNW. Observers on the West Coast have a chance to see the leading dark edge of the Moon occult, or cover, some of the stars of the cluster. From Los Angeles, the first event is at 3:43 a.m. PST, but is only 5° up. From Seattle, the first event is at 3:21 a.m., 17° up.

About 2½ hours after sunset, Aldebaran, eye of Taurus and "Follower" of the Pleiades, is 10° to the Moon's lower right. Capella is 22° to Moon's left. Trace out the huge "Winter Hexagon" or "Winter Ellipse". In clockwise order from Sirius, lowest and brightest member, go around the oval through Procyon, Pollux and Castor, Capella, Aldebaran, Rigel, and back to Sirius. Betelgeuse, Orion's shoulder, is inside the oval.

Please send any comments, suggestions, or questions to Shane Horvatin: horvati3@msu.edu