Archive for August 4, 2021

08/04/2021 – Ephemeris – Let’s search for the naked-eye planets for this week

August 4, 2021 Comments off

This is Bob Moler with Ephemeris for Wednesday, August 4th. Today the Sun will be up for 14 hours and 31 minutes, setting at 9:04, and it will rise tomorrow at 6:33. The Moon, halfway from last quarter to new, will rise at 3:16 tomorrow morning.

Let’s search for the naked-eye planets for this week. Venus can be spotted low in the western twilight by 9:45 pm. It will set at 10:29 pm. Venus will be spending the rest of summer low in the western sky, and not be as conspicuous as it usually is as the Evening Star. Mars is to faint and close to the Sun to be seen from northern latitudes. Saturn, now officially an evening planet, rises before sunset. It will be seen low in the southeast in the evening. Brighter Jupiter will rise at 9:38 pm in the east-southeast and will be seen thereafter trailing Saturn to it’s left or east. Jupiter will join Saturn as an evening planet on the 19th when it too reaches opposition from the Sun.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.


Venus in evening twilight

Venus in evening twilight at 9:45 pm, or about 40 minutes after sunset tonight, August 4, 2021. Created using Stellarium.

Jupiter and Saturn in the SE

Jupiter and Saturn in the Southeastern sky at 10;30 pm tonight, August 4, 2021. Created using Stellarium.

Waning crescent Moon

The waning crescent Moon as it might be seen in binoculars tomorrow morning at 6 am, about an half an hour before sunrise. Created using Stellarium.

The naked-eye planets as seen in small telescopes

Telescopic view of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening, August 4, 2021. Apparent diameters: Venus, 12.93″; Saturn 18.60″, its rings 43.32″; Jupiter, 48.71″. 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).

Note on Jupiter and its moons. The Great Red Spot will be visible on the face of Jupiter. Europa will end its transit of the planet around 11:00 pm (03:00 UT on the 5th) Io will be occulted by Jupiter (behind the planet) in the early evening until about 11:27 pm (03:27 UT on the 5th) and will appear to the east of the planet.

Planets and the Moon overnight tonight

Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on August 4, 2021. The night ends on the left with sunrise on the 5th. Click on the image to enlarge. Created using my LookingUp program.