Archive
10/27/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, October 27th. Today the Sun will be up for 10 hours and 23 minutes, setting at 6:38, and it will rise tomorrow at 8:15. The Moon, 1 day before last quarter, will rise at 11:27 this evening.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7 tonight. It will set at 8:43 pm. By 7:15 pm, Jupiter will be spotted in the south-southeastern sky. Jupiter should be easy to spot at that hour. Saturn will be dimmer, and to its right. They will be visible for a while after midnight in the southwest, with Saturn setting first at 12:37 am, and Jupiter following at 1:57. Saturn’s rings are a beautiful sight in a telescope of even modest power, but the planet will appear tiny. In the morning sky, Mercury will be visible and low in the east-southeast for most of the 7 am hour. All four of Jupiter’s brightest moons will be visible in binoculars early in the evening tonight.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.
Addendum

Jupiter and Saturn in evening twilight at 7:15 pm tonight, October 27, 2021. Created using Stellarium.

The Moon as it might appear in binoculars or a small telescope tomorrow morning, October 28, 2021. Created using Stellarium.

Mercury in morning twilight finder for 7:30 am tomorrow, October 28, 2021. Created using Stellarium.

Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 9 pm, October 27, 2021. Apparent diameters: Venus at 7 pm, 24.19″, 50.8% illuminated; Saturn 16.92″, its rings 39.41″; Jupiter, 42.87″. Mercury at 7:30 am on the 28th and not plotted, 6.47″, 64.9% illuminated. The Jovian moon Io will begin transiting the face of the planet at 9:20 pm. Its shadow will start to cross at 10:37 pm. Io’s transit will end at 11:37 pm. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. Created using Cartes du Ciel (Sky Charts).