This is Ephemeris for Wednesday, September 18th. Today the Sun will be up for 12 hours and 20 minutes, setting at 7:46, and it will rise tomorrow at 7:27. The Moon, 1 day past full, will rise at 8:08 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be spotted in the West southwest only 5° above the horizon at 8:15 or 30 minutes after sunset. It will set at 8:48. Saturn will be low in the east-southeast at that time, with the Moon just rising in the east. Saturn may look disappointing in telescopes this year since its rings are nearly edge on and appearing as a line through the planet like it’s stapled onto the sky. Jupiter and Mars will be up in the morning sky, with Jupiter rising before midnight now and by 6:30 AM tomorrow, Jupiter will be the brightest starlike object in the sky among the winter stars in the south-southeast. Mars will be left and below Jupiter.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Venus in evening twilight, approximately 30 minutes after sunset. For the Grand Traverse area of Michigan that would be about 8:15 PM, where Venus is very close to the horizon, due to the low angle of the ecliptic, even though Venus is about 27 degrees east of the sun, it is only 10 degrees above the horizon at sunset. It would be higher from the south of us, below 45° N latitude, and lower for those north of us. Created using Stellarium.
At the same time we see Venus setting in the West around 8:15 PM we see the Moon rise in the east, and Saturn close by in the east-southeast. Saturn may not be quite as visible as this, but it will be shortly. Created using Stellarium.
The Moon one day past the full Harvest Moon and shadows are beginning to creep onto the west, or right side of it. Created using Stellarium, LibreOffice Draw, and GIMP.
The morning planets Jupiter and Mars are seen among the winter stars at 6:30 AM or about an hour before sunrise in the South southeast. Created using stellarium.
Telescopic Venus, Saturn and Jupiter (north up) as they would be seen in a small telescope with the same magnification. Venus and Saturn are from the evening of the 18th 2024, Jupiter is for 6:30 am on the 19th. Apparent diameters: Venus 11.7″, 87.6% illuminated; Saturn 19.2″, its rings 44.6″, 4.2 degrees from edge on (opening up a bit); Jupiter 40.7″; Mars, too small to be represented here, is 7.1″. The ” means seconds of arc, or 1/3600th of a degree. Click or tap on the image to enlarge it. Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 18, 2024. The night ends on the left with sunrise on the 19th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, September 18 and 19, 2024. Some of the columns are self-explanatory, others not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.
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