Backyard Astronomy: January 2005 (2005-01-01)

By Cheryl Haimann

January offers a parade of planets across the night sky that will please both night owls and early risers. As a bonus, the waning moon is not only pointing the way to some of these planets, but is also improving the view of a comet that recently arrived on the celestial scene.

Comet Machholz

Midwinter is ruled by the constellation Orion, which rises at sunset and is visible all night long. To the upper right of Orion in the early evening is Taurus, marked by the bright star Aldebran, and further on is the Pleiades star cluster.

During the first week of January, Comet Machholz, C/2004 Q2, will be passing to the right (or west) of Aldebaran and the Pleiades. Early in the week, the horns of Taurus, including Aldebaran and the loose star cluster the Hyades, point toward Machholz. The comet and the two clusters will resemble a right triangle. The comet already can be easily viewed in binoculars from a moderately dark city location.

On January 7 and 8, Machholz will be just 2 degrees (four moon-widths) from the Pleiades. It's not known yet whether they comet will be visible to the naked eye, but this weekend will be its most likely opportunity because of its brightness and the nearly moonless conditions. The comet should be visible into the early morning hours.

First time comet watchers should be aware that real comets are not like the literary blazing cometwith a long tail that streaks across the sky.Their motion is apparent from night to night, but in a single viewing session, a comet will appear stationary. Comets are small, often resembling nebulas, and the tail of the comet may or may not be visible to the casual observer.

Evening planet

The first of the night's planets, Saturn, rises about 6:30 PM. It is in Gemini, to the left of Orion. Gemini is identified by the two head stars of the twins Castor and Pollux. Saturn is situated below them, making it appear as though the twins have become triplets. A couple of hours later, follow the arc of the two stars and Saturn on the right to bright stars Procyon (in Canis Minor) and Sirius (in Canis Major, at the feet of Orion.)

Morning planets

At 6:00 AM, Saturn will still be visible in the west. Directly to the south, Jupiter is near Spica, the bright star that marks the tailbone of Virgo. Low in the southeast, Scorpius, with its red heartstar Antares, is rising, accompanied by three planets. Mars is above Antares. Both objects have an orangish color, the source of the name Antares, which means rival of Mars.

Low in the southeast, the two inner planets, Venus and Mercury, will be visible about 45 minutes before sunrise, if you have a clear view of the horizon. Venus is much brighter than pinkish Mercury, and the two planets are only about one degree (two moon widths) apart.

To be sure that you are looking in the right spot, look for the crescent moon near Jupiter on the 4th and 5th, near Mars and Antares on the 7th, and to the right of Venus and Mercury on the 8th.