Archive for December 15, 2021

12/15/2021 – Ephemeris – Let’s search for the naked-eye planets for this week

December 15, 2021 Comments off

This is Ephemeris for Wednesday, December 15th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:02, and it will rise tomorrow at 8:14. The Moon, 3 days before full, will set at 5:50 tomorrow morning.

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, and even binoculars now. It is moving closer to us, and now appears larger than Jupiter in telescopes. Venus will set at 7:27 pm, 14 minutes earlier than it set a week ago, which means that the Sun is catching up with it faster and faster. It has only 24 days left in the evening sky, though it might be hard to spot by the end of the month. 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, halfway between it and Venus. Saturn will set at 8:41 pm, with Jupiter following an hour and a half later at 10:12 pm.

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 in the southwest at 5:45 pm

The evening planets, Venus, Saturn and Jupiter in the southwestern at 5:45 pm Tonight, December 15, 2021. Created using Stellarium.

Waxing gibbous Moon at 6 pm

The waxing gibbous Moon, seen at 6 pm tonight, December 15, 2021. Created using Stellarium.

Mars low in the southeast at 7:20 am

Mars, seen low in the southeast at 7:20 am tomorrow morning, December 16, 2021. Mars was not covered in the recorded program due to time constraints and the fact that Mars, still far away on the other side of the Sun, is only second magnitude and difficult to spot. It will rise at 6:25 am. Created using Stellarium.

Telescopic views of the naked-eye planets

Telescopic views of the bright planets and their brighter moons (north up) as they would be seen in a small telescope, with the same magnification, this evening at 7 pm, December 15, 2021. Apparent diameters: Venus, 49.50″, 15.5% illuminated; Saturn 15.71″, its rings 36.59″; Jupiter, 36.80″. Mars is not shown, its apparent diameter is 3.87″. 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 15, 2021. The night ends on the left with sunrise on the 16th. Click on the image to enlarge it. Created using my LookingUp program.