Bob Moler's Ephemeris Blog

This is Ephemeris for Wednesday, February 4th. Today the Sun will be up for 9 hours and 57 minutes, setting at 5:55, and it will rise tomorrow at 7:56. The Moon, 3 days past full, will rise at 9:25 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object low in the west southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, 2.4 degrees from being edge on and is slowly opening. Jupiter is the brilliant star-like object in the eastern sky, to the right of Pollux in the pair Castor and Pollux, the bright stars of Gemini. It is still moving slowly to the west, and will, until it stops and reverses its track on March 10th. Jupiter’s four brightest moons can be seen even in binoculars, if held steadily enough. They shift position night to night. At 8 PM tonight, all four Galilean moons can be seen, though two may too close together to be picked out separately in binoculars.

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

This is Ephemeris for Wednesday, January 28th. Today the Sun will be up for 9 hours and 39 minutes, setting at 5:45, and it will rise tomorrow at 8:05. The Moon, 3 days past first quarter, will set at 5:43 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, 2 degrees from being edge on and is slowly opening. Jupiter is the brilliant star-like object in the eastern sky, to the right of Pollux in the pair Castor and Pollux, the bright stars of Gemini. It is still moving slowly to the west, and will, until it stops and reverses its track on March 10th. Jupiter’s 4 brightest moons can be seen even in binoculars, if held steadily enough. They shift position night to night. At 8 PM tonight, all four Galilean moons can be seen, though two may too close to the planet to be picked out in binoculars.

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

This is Ephemeris for Wednesday, January 21st. Today the Sun will be up for 9 hours and 23 minutes, setting at 5:36, and it will rise tomorrow at 8:11. The Moon, 3 days past new, will set at 8:53 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the west-southwestern sky as soon as it gets dark. At 8 PM, it is in roughly in the same direction as the Moon, but a good deal higher in the sky. In a telescope Saturn sports a very thin ring, 1.8 degrees from being edge on and is slowly opening. Jupiter is the brilliant star-like object in the eastern sky, to the right of Pollux in the pair Castor and Pollux, the bright stars of Gemini. Jupiter’s 4 brightest moons can be seen even in binoculars, if held steady enough. They shift position night to night. At 8 PM tonight, only three will be visible, but the 4th will be appearing from in front of Jupiter later this evening.

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

This is Ephemeris for Wednesday, January 14th. Today the Sun will be up for 9 hours and 10 minutes, setting at 5:27, and it will rise tomorrow at 8:16. The Moon, halfway from last quarter to new, will rise at 6:14 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, 1½ degrees from being edge on and is slowly opening. Jupiter is now officially an evening planet, rising before sunset. It’s seen in the evening to the right of Pollux in the pair Castor and Pollux, the bright stars of Gemini. Jupiter’s four brightest moons can be seen even in binoculars, and shift position night to night. Jupiter can still be seen in the morning sky. At 7 AM it will be low in the western sky. Venus, Mercury and Mars are too close to the direction of the Sun to be seen.

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

This is Ephemeris for Wednesday, January 7th. Today the Sun will be up for 8 hours and 59 minutes, setting at 5:19, and it will rise tomorrow at 8:19. The Moon, 3 days before last quarter, will rise at 10:37 this evening.

Let’s take our first weekly look at the whereabouts of the naked-eye planets for 2026. Saturn is the brightest star-like object in the southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, 1.2 degrees from being edge on and is slowly opening. Jupiter will rise just after sunset. It is seen in the evening right of Pollux in the pair Castor and Pollux, the bright stars of Gemini. The giant planet is slowly moving westward with its retrograde motion. Jupiter’s 4 brightest moons can be seen even in binoculars, and shift position night to night. In the morning sky, only Jupiter can be seen. It will leave the morning sky, become an official evening planet Saturday. Venus crossed behind the Sun yesterday to become an evening planet. Mars will also cross behind the Sun Friday to become a morning planet.

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

This is Ephemeris for New Year’s Eve, Wednesday, December 31st. The Sun will rise at 8:20. It’ll be up for 8 hours and 52 minutes, setting at 5:12. The Moon, 3 days before full, will set at 6:49 tomorrow morning.

Let’s take our last weekly look at the whereabouts of the naked-eye planets for 2025. Saturn is the brightest star-like object in the southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, one degree from being edge on and is slowly opening. Jupiter will rise at 5:54 PM in the east-northeast, below and right of Castor and Pollux, the bright stars of Gemini. The giant planet is slowly moving westward with its retrograde motion. Jupiter’s 4 brightest moons can be seen even in binoculars, and shift position night to night. In the morning sky, only Jupiter can be seen, descending in the western sky. It will leave the morning sky, officially on January 10th, as it reaches opposition with the Sun.

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

This is Ephemeris for Christmas Eve, Wednesday, December 24th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:06, and it will rise tomorrow at 8:18. The Moon, 3 days before first quarter, will set at 9:51 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southwestern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, eight tenths of a degree from being edge on and slowly opening. Jupiter will rise at 6:26 PM in the east-northeast, below Castor and Pollux, the bright stars of Gemini. The giant planet is slowly moving westward with its retrograde motion. Jupiter’s 4 brightest moons can be seen even in binoculars, and shift position night to night. In the morning sky, only Jupiter can be seen, descending in the western sky. It will leave the morning sky, officially on January 10th, as it reaches opposition to the Sun.

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

A note about transits of Jovian moons: A transiting moon is extremely difficult to pick up, however the moon’s shadow falling on the planet is much more easily spotted.

This is Ephemeris for Wednesday, December 17th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:03, and it will rise tomorrow at 8:15. The Moon, 2 days before new, will rise at 7:26 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, six tenths of a degree from being edge on and slowly opening. In a couple of months the rings will be much more visible in telescopes. Jupiter will rise at 7:02 PM in the east-northeast, below Castor and Pollux, the bright stars of Gemini. Jupiter’s 4 brightest moons can be seen even in binoculars, and shift position night to night. In the morning sky, Mercury just might be spotted very low in the east-southeast by 7:30. The next opportunity to spot Mercury will be in the evening in mid-February.

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

This is Ephemeris for Wednesday, December 10th. Today the Sun will be up for 8 hours and 52 minutes, setting at 5:02, and it will rise tomorrow at 8:10. The Moon, 1 day before last quarter, will rise at 11:45 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, half a degree from being edge on and slowly opening. Normally, I’d say that Saturn’s rings are easy to see in a telescope. In a couple of months the rings will be much more visible in telescopes. Jupiter will rise at 7:29 PM in the east-northeast, beneath Castor and Pollux, the bright stars of Gemini. Jupiter’s 4 brightest moons can be seen even in binoculars, and shift position night to night. Tonight they will all be in line on one side of the planet. Mercury might be spotted very low in the east-southeast by 7 AM tomorrow morning.

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; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

This is Bob Moler with Ephemeris for Wednesday, December 3rd. Today the Sun will be up for 9 hours, setting at 5:02, and it will rise tomorrow at 8:03. The Moon, 1 day before full, will set at 7:59 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star-like object in the southern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, 4/10ths of a degree from being edge on. The rings are slowly opening up. Normally, I’d say that Saturn’s rings are easy to see in a telescope. In a couple of months the rings will be much more visible in telescopes. Jupiter will rise at 8 PM in the east-northeast, beneath Castor and Pollux, the bright stars of Gemini. Jupiter’s 4 brightest moons can even be seen in binoculars, and shift position night to night. Mercury might be spotted low in the east-southeast by 7 AM tomorrow morning, having risen 45 minutes earlier.

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; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum