Minnesota Starwatch is a newsletter describing the night sky in the Midwest.
Updated monthly, it is produced by the
Minnesota Starwatch for January 2017
by Deane Morrison
As New Year's Day fades, a young moon hangs in the southwest near Venus and Mars. And as the sun sets on the last day of January, a young moon again visits the planets, this time coming much closer.
The planets are also approaching each other as Mars drops behind Earth in the orbital race and Venus gets ready to plunge into the sunset on its next trip between Earth and the sun. As usual, Venus is by far the brighter planet. The distance between them shrinks from 11.7 degrees on New Year's Day to 5.4 degrees on the 31st. Try not to miss the Venus-Mars-moon gatherings, especially the one on the 31st.
For morning viewers, Saturn makes an entrance in the southeast, climbing higher and appearing earlier every day. By the third week of January it will be easily visible an hour before sunrise, with the red star Antares, in Scorpius, off to the right. High in the south, Jupiter shines brightly during the predawn hours all month. It rises several hours ahead of Saturn and travels the sky above Spica, the bright star in Virgo.
January's full moon was known to many Algonquin Indians as the wolf moon, for the hungry howling of wolf packs in the deep snow. It reaches fullness at 5:34 a.m. on the 12th. At that moment it will shine in the west, between the Gemini twins and the bright star Procyon in Canis Minor.
As it wanes, the moon visits the morning planets. It appears near Jupiter on the 19th, when it will be almost at last quarter phase, and a lovely crescent rises close to Saturn on the 24th.
The bright winter stars are now coming into their own and will all be up in the east by about 8 p.m. Like a reigning monarch, Sirius, the brightest of all, is the last to make its entrance.
On the 4th Earth reaches perihelion, the closest point to the sun in our orbit. On that day, we will swoop to 91.4 million miles from our parent star. In comparison, we will be 94.5 million miles away at aphelion, our farthest distance, in early July. The distance has nothing to do with the difference in seasons, though; the January cold happens because the Northern Hemisphere is now tilted away from the sun. On the bright side, planets move faster when they are near perihelion, and this means that Northern Hemisphere dwellers do not have as long a wait between the onset of autumn and the onset of spring as do our Southern Hemisphere counterparts.
Duluth, Marshall W. Alworth Planetarium: www.d.umn.edu/planet
Twin Cities, Minnesota Institute for Astrophysics (during fall and spring semesters): www.astro.umn.edu/outreach/pubnight
Check out the astronomy programs at the University of Minnesota's Bell Museum ExploraDome: www.bellmuseum.umn.edu/ForGroups/ExploraDome/index.htm
12/20/16 Contact: Deane Morrison, University Relations, (612) 624-2346,
Find U of M astronomers and links to the world of astronomy at http://www.astro.umn.edu.