Jane Houston Jones: What's Up for December. Bright planets, a Comet ISON status report plus wintery starry sights. Hello and welcome. I'm Jane Houston Jones from NASA's Jet Propulsion Laboratory in Pasadena, California.
Observers definitely saw Comet ISON brighten and change in November.
If the comet survived perihelion, its closest approach to the sun, it will be visible both before dawn and after sunset this month. It will appear higher in the sky at dawn than at sunset, providing a better chance to see it. During the second half of December, Comet ISON should fade rapidly as it moves north. It will be closest to Earth in its orbit on December 26.
Jones: You may have noticed a very bright 'star' in the western sky. That's Venus! Venus shines at its very brightest, magnitude -4.9 this month. It sets about 3 hours after sunset at the beginning of the month and one and a half hours after sunset at the end of the month. This is a great month to view the dramatic changes in the apparent diameter and phases of Venus as it races towards its conjunction with the sun. The first observations of the phases of Venus were made by Galileo in 1610!
Jones: Mars continues to grow brighter and rises near midnight, and Jupiter rises earlier in the evening, heralding the best viewing season for Jupiter watchers.
Jones: The beautiful Geminid meteor shower will only slightly be marred by moonlight on the night of December 13 and 14. The radiant lies near Gemini with brilliant Jupiter above and the constellation Orion below. From a dark sky, but even from the city, the mighty hunter Orion is easily visible in the southeast sky. Take a look at Orion's shoulder star, red Betelgeuse and its knee star, blue Rigel and the Orion Nebula.
You can see the latest images of Comet ISON from space telescopes and worldwide amateurs at
And you can see space images and learn about all of NASA's missions at http://www.nasa.gov.
That's all for this month. I'm Jane Houston Jones.
Page Editor: Tony Greicius