The December sky is one in transition. The Summer Triangle is still visible in the evening as darkness falls; the stars of autumn are overhead and those of winter rise later in the evening. Two meteor showers occur, and the sky is filled with planets from twilight to morning.
Venus is the first planet visible, right after sunset. Hanging low and bright in the west, it is often mistaken for a UFO. You can actually see Venus change phases, like the moon, but it is still too low in the sky in December to be able to get a clear look at without turbulence from the atmosphere. Use Venus as a guide during the first half of December to find the yellowish planet Mercury, to the lower right of Venus (one field of view away). You can measure a field of view by placing your fist at arm's length. The area of your fist covering the sky is approximately a field.
Mars is still visible, but it appears considerably smaller since its incredible appearance this summer. Mars shines in the southern sky. In larger telescopes, you can still see some faint surface details, but the magnificent show put on by the Red Planet in August is definitely over.
Saturn rises soon after sunset, and is a bright-gold object in the constellation Gemini. This month, on New Years Eve, Saturn will be at opposition, which means it is opposite the sun in the sky. When a planet is at opposition, "it is at its best," appearing at sunset and remaining visible until dawn. Saturn is famous for its beautiful ring system, which can only be slightly seen in binoculars. A telescope is needed to appreciate the rings, and with a medium size telescope, you can also see some faint surface features. Saturn is a lovely planet to look at through either binoculars or a telescope.
Jupiter rises in the east shortly before midnight by the middle of the month. Jupiter is a very interesting planet to look at. With binoculars, you can see the four largest moons of Jupiter. They change position every night, almost appearing to "dance" around the planet. With a telescope, you can see many features on Jupiter's surface, including the famous Red Spot, which is a storm that has been raging on Jupiter for years. With a telescope, you can watch the Red Spot make a transit, or move, across the surface. Transit times are listed at most of the major astronomy websites. Use the moon in the mid-morning sky on December 16 to find Jupiter below it during broad daylight.
