Starwatch Newsletter Minnesota Starwatch is a tape-recorded message describing the night sky in the Midwest, which can be called by telelphone number (612) 624-2001 It is updated montly, and is produced by the Department of Astronomy, University of Minnesota 116 Church Street SE, Minneapolis, MN 55455

December means winter in the northern hemisphere and the winter solstice, which occurs when the Sun is at its furthest southern position in the sky, making it the shortest day of the year. This year the solstice is on December 21st at 7:56pm (CST).

While the winter solstice is the shortest day of the year for us, it is not the day of the earliest sunset or the latest sunrise. Because of the tilt of the Earth's axis, which causes the seasons and the ellipticity of the Earth's orbit, the Sun, as a clock, appears to be several minutes ahead of schedule or running fast in the fall and running slow in the winter. This slow-fast variation is called the equation of time. If you plot the Sun's position in the sky at the same time every day of the year, it would trace a figure 8 on the sky. Astronomers call this the analemma.

At this time of year the days are getting shorter, but before the solstice, the Sun is running fast so the earliest sunset comes around December 7th, while after the solstice, the Sun is running slow and the latest sunrise is around January 4th.

There has been a lot of attention to the Leonid meteor "storm" in November, which wasn't well situated for observers in the western hemisphere, but there is another meteor shower expected in December, the Geminids, which will be easy to observe for us in Minnesota. The shower will be visible after 10:00pm on the nights of December 13th and 14th, and if recent past events are any clue, about 100 meteors will be seen hourly, although being away from city lights helps.

Also this month Venus returns to the evening sky and can be seen low in the southwestern sky just after sunset. Jupiter will be very noticeable in the south-southeastern sky, while Saturn can be found behind, or rather just east, of Jupiter. Both planets will be prominent in the southern sky after dark, but Mars, on the other hand, will not rise until after midnight. Mercury will be easier to see than usual; by mid-December it will be visible in the east-southeast about 1 hours before sunrise.

The Minneapolis Planetarium offers Starshows at various times. Current titles are "Tis the Season" and "A Christmas Present." The Planetarium also offers its adult show, Skywatch, showing at noon on the first Monday of the month and again at 7:00pm the first and third Wednesday of the month. The Skywatch show for December is "Rainbows, Green Flashes, Moondogs, and Other Amazing Effects." The Planetarium is located in the main branch of the Minneapolis Public Library at 300 Nicollet Mall. Please call their recorded message at 630-6150 for more detailed information on show times and prices.

The Minnesota Astronomical Society, the local club of amateur astronomers, meets in the auditorium of the Science Museum of Minnesota on St. Paul on Tuesday, December 1st at 7:30pm. To learn more about this month's Astronomical Society activities, call their recorded message at 649-4861.

Minnesota Starwatch as well as other public outreach items are now available on-line! The URL address is http://ast1.spa.umn.edu/Outreach/pub_out.html.

This has been Minnesota Starwatch, produced by the University of Minnesota Astronomy Department in cooperation with the WCCO Weather Center.

Last Updated: Tue Nov 17 12:45:16 1998