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10/28/2022 – Ephemeris – Mars is turning around this weekend
This is Bob Moler with Ephemeris for Friday, October 28th. Today the Sun will be up for 10 hours and 21 minutes, setting at 6:37, and it will rise tomorrow at 8:16. The Moon, 3 days past new, will set at 8:39 this evening.
This Sunday the 30th, the planet Mars will cease its normal eastward motion in relation to the stars, and backtrack to the west for a while. The instant Mars stops its eastward motion, it is said to be stationary. The backtracking is called retrograde motion, which was hard for ancient astronomers to explain because they thought the Earth was not moving and in the center of the universe. And the planets moved in uniform circular motion. So said the Greeks, because they thought that things in the heavens were perfect, not like the imperfect things of the Earth. Mars was a hard case. Its motion was definitely not uniform or circular. To Copernicus, the retrograde motion meant that the Earth was a planet passing another planet in their race around the Sun.
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
Mars retrograde path from October 29, 2022 to January 11, 2023 against the stars of Taurus the bull. It will be at opposition on December 7, and actually closest to the Earth on November 30 at 50.61 million miles or 81.45 million kilometers. In the upper right is the beautiful Pleiades star cluster, also known as the Seven Sisters. Below and right is the V shaped star cluster that represents the face of Taurus the bull, with the bright red star Aldebaran as the bull’s angry red eye. That V of stars is called the Hyades, who in mythology were the half sisters to the Pleiades. Click on the image to enlarge it. Created using Cartes du Ciel (Sky Charts) and GIMP.
10/18/2021 – Ephemeris – Jupiter is stationary today
This is Ephemeris for Monday, October 18th. Today the Sun will be up for 10 hours and 50 minutes, setting at 6:52, and it will rise tomorrow at 8:03. The Moon, 2 days before full, will set at 6:49 tomorrow morning.
The planet Jupiter is stationary today after moving westward for the last four months, as the Earth passed it in our race around the Sun. And it will resume its normal prograde or eastward motion against the stars and constellations of the Zodiac. During this retrograde time it had seemed to move closer to Saturn. Now that it and Saturn are appearing to resume their eastward motion, Jupiter again will appear to open up the distance between them. The ancient Greeks had a devil of a time trying to model this behavior, because they started with two false premises. One, that the Earth was stationary in the center of the universe; and two, that the Sun, Moon, and planets moved in uniform circular motion because they were perfect.
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’s apparent motions seen against the constellation of Capricornus in 2021, including their retrograde loops. Click on the image to enlarge it. The tracks begin on the right. By the end of 2021 neither planet recovers all the eastern progress they lost in their retrograde loops. Created using Cartes du Ciel (Sky Charts).
Bob Moler's Ephemeris Blog 