Archive for May 12, 2021

05/12/2021 – Ephemeris – Searching for the naked-eye planets for this week

May 12, 2021 Comments off

This is Ephemeris for Wednesday, May 12th. Today the Sun will be up for 14 hours and 43 minutes, setting at 9:01, and it will rise tomorrow at 6:16. The Moon, 1 day past new, will set at 10:06 this evening.

Let’s search for the naked-eye planets for this week. Mars will be joined by two more planets seen in twilight. Both Mercury and Venus are now just above where the Sun set. By 9:30 pm Mercury should be able to be spotted low in the west-northwest. Venus might be spotted lower and somewhat earlier. Venus will be setting at 10:02 pm with Mercury following at 11 pm. Mars can be found in the west at 10 pm tonight, in the constellation of Gemini the twins. Tonight it’s in the middle of the constellation. Mars will set at 1:02 am. Jupiter and Saturn, are in the morning sky. Saturn will rise at 2:30 am, with brighter Jupiter rising at 3:13 am. By 5:30 am they will be low in the southeast in the morning twilight.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Mercury and Venus low in the west-northwest tonight at 9:30 pm or a half hour after sunset. The one-day-old Moon appears just to the left of Venus. Mercury will be 14 degrees above the Lake Michigan horizon, and Venus only 5 degrees. By tomorrow night, the Moon will be to the left of Mercury. Created using Stellarium.
Mars finder animation for 10:30 pm tonight or about an hour and a half after sunset. Bonus: Mercury is still up. Created using Stellarium and GIMP.
Jupiter and Saturn in morning twilight tomorrow morning May 23, 2021. Created using Stellarium.
Saturn and Jupiter as seen in a small telescope at the same magnification. Apparent diameters: Saturn, 17.05″, rings, 39.71″; Jupiter, 38.83″. Mars is too far away to make out detail on its surface, except maybe a polar cap. Its apparent diameter is 4.43″. Venus’ apparent diameter is 9.97″ and will be added when it gets far enough from the Sun to be easily seen. Mercury’s apparent diameter is 7.29″. The cutoff for whether to show a planet here is an apparent diameter of 10″ or greater. The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts).
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on May 12, 2021. The night ends on the left with sunrise on the 13th. Click on the image to enlarge. Created using my LookingUp program.