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Ephemeris: 12/26/2025 – Conjunctions, eclipses, transits and occultations, oh my!
This is Ephemeris for Friday, December 26th. Today the Sun will be up for 8 hours and 49 minutes, setting at 5:08, and it will rise tomorrow at 8:19. The Moon, 1 day before first quarter, will set at 12:13 tomorrow morning.
Tonight the Moon will pass north of the planet Saturn. That will mean in that location in the southwestern sky, the planet will appear just below and left of the Moon. When two solar system objects appear to pass each other, it’s called a conjunction. To astronomers, it’s no big deal unless one passes directly in front of the other. If a smaller appearing one crosses the disc of a larger one, it’s called a transit, If one is completely hidden by another it’s an occultation. Occultations and transits of Jupiter and its satellites are common. Also, Jupiter’s satellites are eclipsed by passing through the planet’s shadow. We are in a period now when Jupiter’s moons occult and eclipse each other occasionally.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 12/22/2025 – The most popular astronomical explanation for the Star of Bethlehem
This is Ephemeris for Monday, December 22nd. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:05, and it will rise tomorrow at 8:18. The Moon, 3 days past new, will set at 7:30 this evening.
This year we have a bright evening Christmas star, Jupiter in the east. But what about the one described in the Bible, in the Gospel of Matthew? We will look today at the first of two events that may have been recorded as the Star of Bethlehem. In 7 BCE there was a rare event over 6 months when three times the planet Jupiter passed Saturn against the stars of the constellation Pisces. Could the Persian astrologer priests, called Magi, have read into the event enough significance to start the journey to Jerusalem in search of the newborn King of the Jews? It was the scribe’s readings that sent them to Bethlehem. Jupiter, Saturn and Pisces all may have had significance to the Magi.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
05/21/2013 – Ephemeris – Dances with Planets
Ephemeris for Tuesday, May 21st. Today the sun will be up for 15 hours and 2 minutes, setting at 9:10. The moon, 3 days past first quarter, will set at 4:17 tomorrow morning. Tomorrow the sun will rise at 6:07.
Over the next week there will be a planet grouping low in the west about 10 p.m. as Jupiter continues it slide toward the sun while Venus and Mercury move away from the sun. Mercury will earn its title as the messenger of the gods, and fastest planet by overtaking Venus and Jupiter on consecutive nights. The group of the three planets will be their most compact on Sunday night he 26th. Tonight however Mercury will be to the right and a bit below Venus with Jupiter above and left of them both. Tomorrow night Mercury will have moved to be almost level with Venus, while Jupiter drops toward them. On bobmoler.wordpress.com there is an animation of these planets for the next 8 days.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Dance of the planets Jupiter, Venus and Mercury, May 21 thru May 28, 2013. Created using Stellarium. Click on the image to start animation.
05/25/2012 – Ephemeris – Of conjunctions, superior and inferior
Ephemeris for Friday, May 25th. Today the sun will be up for 15 hours and 10 minutes, setting at 9:14. The moon, 3 days before first quarter, will set at 12:45 tomorrow morning. Tomorrow the sun will rise at 6:03.
The planet Mercury will pass the behind the sun this weekend, in what is called superior conjunction. It is called that because Mercury is beyond or superior to the sun. Venus and Mercury can have both superior and inferior conjunctions because they are inferior planets, not a statement of their quality, but simply because they reside in orbits between the earth and the sun. A conjunction occurs when two solar system bodies pass each other from our point of view. Anyway Mercury will slowly move into our evening sky and by July first might be glimpsed in evening twilight. Mercury can be seen near its greatest elongations or separations from the sun on spring evenings and autumn mornings. July will push it a bit.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 