Earth’s winter solstice occurs at 5:23 p.m. EST. At that moment, the Sun reaches its farthest point south in the sky. The solstice marks the official beginning of winter in the Northern Hemisphere, and tonight has more hours of darkness than any other. From mid-northern latitudes, however, the earliest sunset occurred about two weeks ago and the latest sunrise won’t happen until early January.Full Moon officially arrives at 12:49 p.m. EST, but our satellite looks completely illuminated all night. You can find it rising in the east just after sunset and peaking in the south shortly after midnight local time. It dips low in the west by the time morning twilight begins. As the Full Moon closest to the winter solstice, it climbs higher in the sky than any other Full Moon during the year. It lies among the background stars of western Gemini tonight, near the feet of the Twins.Mercury remains a nice sight in predawn twilight for the next several days. This morning, the innermost planet lies 7° above the southeastern horizon 45 minutes before sunrise. Mercury shines at magnitude –0.4, easily bright enough to see with the naked eye (although binoculars will help you pick it out of the twilight glow). Simply look 2° to the lower left of brilliant Jupiter, which shines about four times brighter than the inner world. When viewed through a telescope, Mercury appears 6" across and shows a gibbous phase.

The solar system’s two outer planets both have close encounters with stars this evening. Look for Uranus some 60° above the southern horizon around 7:30 p.m. local time. The magnitude 5.7 world lies in southeastern Pisces, 1.3° north of 4th-magnitude Omicron (ο) Piscium. Although Uranus shines brightly enough to glimpse with the naked eye under a dark sky, use binoculars to locate it initially. A telescope reveals the planet’s 3.6"-diameter disk and striking blue-green color as well as a neighboring point of light that looks a bit like a moon. But this is actually a 9th-magnitude field star that slides 1' south of Uranus this evening. Once you’ve finished viewing Uranus, turn your scope toward Neptune. The magnitude 7.9 world lies 2.2° east of 4th-magnitude Lambda (λ) Aquarii, an area that appears 30° high in the southwest at 7 p.m. local time. This evening, Neptune lies 15' (half the Full Moon’s diameter) due south of 6th-magnitude 81 Aqr. Higher magnifications reveal Neptune’s blue-gray disk, which spans 2.3".

The Moon reaches perigee, the closest point in its orbit around Earth, at 4:49 a.m. EST. It then lies 224,353 miles (361,062 kilometers) away from us.