Archive for December 8, 2021

12/08/2021 – Ephemeris – Let’s search for the naked-eye planets and a comet for this week

December 8, 2021 Comments off

This is Ephemeris for Wednesday, December 8th. Today the Sun will be up for 8 hours and 54 minutes, setting at 5:02, and it will rise tomorrow at 8:08. The Moon, 2 days before first quarter, will set at 10:00 this evening.

Let’s search for the naked-eye planets for this week. Venus will be visible in the southwestern evening twilight by 5:30 tonight. It’s a crescent in telescopes. It is moving closer to us, and now appears larger than Jupiter in telescopes. Venus will set at 7:41 pm. By 5:45 pm, both Jupiter and Saturn should be able to be spotted in the southwestern sky. Saturn will be dimmer, and to its lower right, between it and Venus. It will set at 9:05 pm, with Jupiter following an hour and a half later at 10:34 pm. Comet Leonard can be spotted with binoculars about 19 degrees below and a bit left of the bright star Arcturus in the east from 6 to 7am tomorrow morning. 19 degrees is a bit less than two widths of a fist held at arm’s length. The comet will move lower each morning.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.


Evening planets at 5:45 pm

The evening planets Venus, Saturn, the Moon and Jupiter at 5:45 pm this evening, December 8, 2021. Created using Stellarium.

Comet Leonard and Mars in the morning

Comet Leonard and Mars at 7:15 am tomorrow morning, December 9, 2021. Though technically visible to the naked eye, binoculars will be needed for most of us. Mars is now visible low in the southeast at that time. Created using Stellarium.

Telescopic views of the naked-eye planets

Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 6 pm, December 8, 2021. Apparent diameters: Venus, 44.08″, 21.5% illuminated; Saturn 15.84″, its rings 36.90″; Jupiter, 37.51″. Mars is not shown, its apparent diameter is 3.82″. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on December 8, 2021. The night ends on the left with sunrise on the 9th. Click on the image to enlarge it. Created using my LookingUp program.

Comet Leonard (C/2021 A1) in the morning

Comet Leonard’s positions at 6:30 am on the dates indicated. The labels are Month-Day Total Magnitude. The star’s position relative to the horizon and the position of Mars are for November 27th. The star field will be shifting to the upper right each morning at 6:30 from the November 27th date at 6:30. Comets always appear dimmer than their magnitude suggests because they are extended objects, not points like stars. Also, comet magnitudes can be unpredictable. Created using Cartes du Ciel (Sky Charts). I’ve reversed the colors from previous printings of this image. Reprinted from my article in the Stellar Sentinel, the newsletter for the Grand Traverse Astronomical Society.