This fall, a research team led by Jan Hollis of NASA’s Goddard Space Flight Center used a 12-meter radio telescope atop Kitt Peak in Arizona to detect the presence of a simple sugar near the center of our galaxy. The sugar, glycoaldehyde, can combine with other molecules to form more complex sugars.

“The discovery of this sugar molecule in a cloud where stars are forming,” says Hollis, “means it is increasingly likely that chemical precursors to life are formed in interstellar clouds before planets develop.” About 120 different molecules have been discovered in interstellar clouds.

Focus on the planets

Mercury may appear momentarily on the eastern horizon before disappearing into the morning twilight early in December.

Venus blazes high in the southwest at dusk. The “evening star” has an extremely close pairing with the crescent moon on the 29th of the month.

Mars rises three hours after midnight and is high in the southeast at dawn. The Red Planet will grow slightly in size and brightness during the month.

Jupiter is well up on he eastern horizon as darkness falls and remains in view nearly all night.

Saturn rises shortly before Jupiter and is found to the upper right of the giant planet. Look for a triangle consisting of Jupiter, Saturn and a nearly full moon on the 9th of the month.

Uranus can be spotted with binoculars on the western horizon about two hours after sunset. Venus, which lies about a degree southeast of Uranus, can be used as a starting point to locating the distant planet on the nights of the 23rd and 24th.

Neptune will be hard to spot without a telescope and finder chart, with the best opportunity coming Dec. 1 when the moon passes 3 degrees to the south.

Pluto is lost to view all month.

Focus on a constellation

The Summer Triangle is now disappearing over the western horizon and the Autumn Square, or the square of Pegasus, also will soon be but a memory.

Taking their place to mark the winter months are six stars roughly assembled as the Winter Hexagon. The star chart shows these as being Castor in Gemini; Capella in Auriga; Aldebaran, the “red eye” of Taurus the Bull; Rigel, the “Mariner’s Star,” in Orion; Sirius the “dog star,” and Procyon in Canis Minor. The hexagon is expanded in some books of constellations with the addition of Pollux in Gemini and Betelgeuse in Orion. It then reminds observers of the letter “G” and is given the name, the “heavenly G.” Regardless of how many stars are included, this distinctive grouping not only heralds the winter months, but is also a landmark by which many of the major winter constellations can be identified.

December events

1 Sunrise, 6:52 a.m.; sunset, 3:56 p.m.

3 Fomalhaut, the “autumn star,” shines below the moon tonight. It belongs to the constellation Piscis Austrinus, the “southern fish,” and is the only major southern constellation seen in the Northern Hemisphere.

4 Moon in first quarter, 10:55 a.m.

9 The moon, Saturn and Jupiter form a tight triangle in the evening sky.

11 Full moon, 4:04 a.m. The full moon of December is called the “Long Night Moon” or “Moon Before Yule.”

13 The annual Geminid meteor shower peaks tonight. Normally one of the year’s best showers, it will be seriously hindered by bright moonlight.

17 Sun enters Sagittarius on the ecliptic.

18 Moon in last quarter, 7:43 a.m.

19 The moon shines above orange Mars and blue-white Spica in the southeast shortly before dawn.

21 Winter solstice, 8:37 a.m. The sun reaches its farthest point south of the equator with days shortest and nights longest in the Northern Hemisphere. Sun enters the astrological sign of Capricornus but astronomically is still in Sagittarius.

25 Merry Christmas. Celebrate by noting the partial eclipse of the sun taking place today. It will occur around midday and should reduce the sun to a thick crescent. New moon, 12:22 p.m.

29 Venus and the moon are a close couple in the evening sky.

31 Sunrise, 7:13 a.m.; sunset, 4:04 p.m.