Planets | Bob Moler's Ephemeris Blog

Ephemeris: 01/15/2025 – Our weekly look at the whereabouts of the naked-eye planets

January 15, 2025 bobmoler Comments off

This is Ephemeris for Wednesday, January 15th. Today the Sun will be up for 9 hours and 12 minutes, setting at 5:28, and it will rise tomorrow at 8:15. The Moon, 2 days past full, will rise at 7:27 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. At 8 PM this evening four of the five naked eye planets will be out. Starting from the West we have Venus the brightest of all low in the west southwest. Left and a bit above it is Saturn. They will appear at their closest Friday and Saturday nights. Jupiter, the second-brightest planet will be high in the southeast. The 4th planet out is Mars, which is at opposition from the Sun tonight. Mars will not get this close to the Earth again until 2031. It shines with its reddish hue a third as bright as Jupiter in the eastern sky. On unusually close approaches, Mars can actually outshine Jupiter. The fifth naked eye planet, Mercury, is too close to the Sun on the morning side to be visible.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

A 8 PM January 15, 2025 planet panorama. Venus and Saturn are in the west-southwest, and Jupiter is in the southeast. Mars is in the east-northeast. The waning gibbous Moon is rising in the east-northeast. The first magnitude stars are also named. Click or tap on the image to enlarge it. Created using Stellarium.

*The Moon tonight at 9 PM, January 15, 2025, as it might appear in a small telescope. Selected features are labeled. Created using Stellarium, LibreOffice Draw, and GIMP.*

Translations of some lunar feature names according to Virtual Moon Atlas

Mare Cognitum – Sea of Knowledge
Mare Crisium – Sea of Crises
Mare Fecunditatis – Sea of Fruitfulness
Mare Frigoris – Sea of Cold
Mare Humorum – Sea of Moisture
Mare Imbrium – Sea of Showers
Mare Nectaris – Sea of Nectar
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Tranquillitatis – Sea of Tranquility
Mare Vaporum – Sea of Vapors
Montes Alpes – Alps Mountains
Montes Apenninus – Apennines Mountains
Oceanus Procellarum – Ocean of Storms
Sinus Iridium – Bay of Rainbows
Sinus Medii – Central Bay

Mare is pronounced Mar-e. Craters are named for persons, real or otherwise.

Telescopic Venus, Saturn, Jupiter and Mars (north up) as they would be seen in a small telescope with the same magnification. All the planets are shown for tonight, 8 PM, January 15, 2025. Apparent diameters: Venus 26.1″, 47.8% illuminated; Saturn 16.2″, its rings 37.8″, 3.7 degrees from edge on (closing); Jupiter 45.5″; Mars, 14.6″. Planetary surface detail is more subtle than shown here. Jupiter’s moon Europa is behind the planet and will reappear on Callisto’s side of the planet at 9:22 PM (2:22 UT). 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 January 15, 2025. The night ends on the left with sunrise on the 16th. 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, January 15 and 16, 2025. 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.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mars, Mercury, Moon, Saturn, Venus

Ephemeris: 01/10/2025 – Venus’ split personality

January 10, 2025 bobmoler Comments off

This is Ephemeris for Friday, January 10th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:22, and it will rise tomorrow at 8:18. The Moon, 3 days before full, will set at 6:40 tomorrow morning.

In very ancient times the Greeks thought that Venus in the evening as we see it now and Venus in the morning sky were two separate planets. The evening appearance was Aphrodite the goddess of love, and in the morning sky it was Phosphorus, the bringer of light, that being dawn. In Roman times Aphrodite became Venus and Phosphorus became Lucifer. It is interesting that Venus and Aphrodite are female while Phosphorus and Lucifer are male. Another term for Venus which I even use colloquially, is Evening Star for its current location and Morning Star in the morning sky, even though it’s a planet not a star. Venus is a beautiful planet in our sky, but a hellish planet in reality. No wonder Elon Musk would rather go to Mars than the much closer Venus.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

Two greatest elongations of Venus from the Sun this year — Here are the two greatest elongations of Venus from the Sun this year. Yesterday’s greatest eastern elongation and below, on May 31st, the greatest western elongation of Venus in the morning. So indeed, it is the same planet seen alternately in the morning and in the evening sky. I’m showing you below the horizon, so that the red orbit of the planet is seen in its entirety. Created using Stellarium, Libreoffice Draw, and GIMP.

Categories: Ephemeris Program, Planets, Venus Tags: Venus

Ephemeris: 01/09/2025 – Venus is at its greatest separation from the Sun today

January 9, 2025 bobmoler Comments off

This is Ephemeris for Thursday, January 9th. Today the Sun will be up for 9 hours and 2 minutes, setting at 5:21, and it will rise tomorrow at 8:18. The Moon, 3 days past first quarter, will set at 5:25 tomorrow morning.

Tonight, Venus will be at its greatest separation from the Sun in the sky at a little bit more than a 47° angle. Venus, being inside the Earth’s orbit, can ever stray far from the Sun. So today it is at its greatest eastern elongation from the Sun. For the rest of winter it will be moving closer to the Sun from our perspective. Crossing between the Earth and the Sun on March 22nd. During this period of time Venus will be a great object for the telescope, as it moves closer to the Earth and gets larger in telescopes and its phase, moving from being like a quarter moon to a very thin crescent near the end of winter. At inferior conjunction with the Sun, Venus will be only 26 million miles away from us, but quite invisible in the Sun’s glare.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

The Mayan civilization of Central America had several calendars. One of them was based on the planet Venus. They discovered that Venus repeated its positions in the sky with respect with the seasonal calendar over a period of eight years, which they called a Venus Sequence. They paid close attention to Venus and discovered it appeared to go around the Sun in the sky in 584 days, which they called a Venus Cycle. We call it Venus’ synodic period, which is the number of days between inferior conjunction, when Venus passes between the Earth and the Sun, then moves through the morning sky, and disappears behind the Sun at superior conjunction, then appears in the evening sky and back to inferior conjunction again. The gray area in the diagram is where Venus is not visible because it’s too close to the sun. However, at our latitude the number of days that Venus is invisible varies with the season. The Mayans, being in the tropics, didn’t have as much variation as we do. The Mayans discovered that Venus completed 5 cycles in almost exactly 8 years.

Today, Venus is at its greatest eastern elongation. On March 22nd Venus will pass inferior conjunction. That is 72 days from today. So it spends most of its time, 7 months, moving from around behind the Sun to the greatest elongation and only a short time, about 2 1/2 months moving from there to inferior conjunction. These 2 1/2 months are the best time to view Venus with a telescope, since Venus will grow in size and become an ever thinning crescent.

Check out my Wednesday posts showing the ever-growing and thinning Venus crescent until March 22nd. Or better yet, see it for yourself with a small telescope.

Categories: Concepts, Ephemeris Program, Planets Tags: Greatest eastern Elongation, Maya, Venus, Venus Cycle

Ephemeris: 01/08/2025 – A weekly look at the whereabouts of the naked-eye planets

January 8, 2025 bobmoler Comments off

This is Ephemeris for Wednesday, January 8th. Today the Sun will be up for 9 hours and 1 minute, setting at 5:20, and it will rise tomorrow at 8:18. The Moon, 2 days past first quarter, will set at 4:05 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. At 8:00 PM this evening four of the five naked eye planets will be out. Starting from the West we have Venus the brightest of all low in the west southwest. Above and left of that is Saturn. The waxing gibbous moon is high in the South at that time. Jupiter, the second-brightest planet will be high in the southeast. The 4th planet out is Mars which is low in the east northeast with its reddish hue giving it away. Next Monday the Moon will pass directly over the planet Mars in our evening sky. The fifth naked eye planet, Mercury, is too close to the Sun on it morning side to be visible.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

A 7 PM January 8, 2025, planet panorama — A 7 PM January 8, 2025 planet panorama. Venus and Saturn are in the southwest, and Jupiter is in the east. Mars is just rising in the east-northeast. Click or tap on the image to enlarge it. Created using Stellarium.

*The Moon tonight, January 8, 2025, as it might appear in a small telescope. Selected features are labeled. Created using Stellarium, LibreOffice Draw, and GIMP.*

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on January 8, 2025. The night ends on the left with sunrise on the 9th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow — This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, January 8 and 9, 2025. 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.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mars, Mercury, Moon, Saturn, Venus

Ephemeris: 01/06/2025 – Things that go blink in the night

January 6, 2025 bobmoler Comments off

This is Ephemeris for Monday, January 6th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:18, and it will rise tomorrow at 8:19. The Moon, at first quarter today, will set at 1:26 tomorrow morning.

Lately there’s been a lot of reported observations of drones or various things in the sky at night, especially, for some reason, in New Jersey. If it’s something that’s moving in the sky other than satellites, meteors and aurorae, they’re out of my wheelhouse. I generally concern myself with the sidereal universe, the universe beyond the atmosphere. Things that don’t seem to move that rapidly. There are a lot of bright lights in the sky, that are things that I can and do talk about this time of year and this particular year. We have a lot of bright lights in the sky now, foremost Venus in the southwest in the early evening, and Jupiter in the east and the south. Mars is also up, but it’s not in competition with Jupiter this year. These plus the bright winter stars.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

Bright lights in the sky, namely the Moon, planets, and Venus at 8:00 PM tonight. This image encompasses a angle of nearly 180° wide and 70° tall. Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

Categories: Ephemeris Program, Observing, Planets, Stars, The Moon Tags: Lights in the sky

Ephemeris: 01/01/2025 – A New Year’s Day look at the naked-eye planets

January 1, 2025 bobmoler Comments off

This is Ephemeris for New Year’s Day, Wednesday, January 1st, 2025. The Sun will rise at 8:20. It’ll be up for 8 hours and 53 minutes, setting at 5:13. The Moon, 2 days past new, will set at 7:02 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted in the south-southwestern sky by 5:45 PM, about 30 minutes after sunset, and will also be above and left of the thin crescent Moon. Venus will set at 9:10 PM. Saturn will be in the south-southwestern sky at 6 PM, above and left of Venus, which will be seen to cross paths with it on the 18th of this month. Jupiter is low in the east, about the same time Venus is first spotted. It will be a good object for the small telescope. Mars, rises tonight at 6:31. Mars is still considered a morning planet since it is still up at sunrise. But that will end on the 15th of this month, when Mars reaches opposition from the Sun.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Happy New Year! I do really hope it will be happy…

Addendum

This is a 7 PM planet panorama. Venus and Saturn are in the southwest, and Jupiter is in the east. Mars is just rising in the east-northeast. Click or tap on the image to enlarge it. Created using Stellarium.

*The waxing two day old Moon with earthshine on its night side. Created using Stellarium.*

Telescopic Venus, Saturn, Jupiter and Mars (north up) as they would be seen in a small telescope with the same magnification. All the planets are shown for tonight, Jupiter specifically for 7 PM, January 1, 2025. Apparent diameters: Venus 22.4″, 55% illuminated; Saturn 16.6″, its rings 38.6″, 4.3 degrees from edge on (closing); Jupiter 47.0″; Mars, 14.3″. Planetary surface detail is more subtle than shown here. 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 January 1, 2025. The night ends on the left with sunrise on the 2nd. 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, January 1 and 2, 2025. 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.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mercury, Moon, Saturn, Venus

Ephemeris: 12/25/2024 – A Christmas week look at the naked-eye planets

December 25, 2024 bobmoler 1 comment

This is Ephemeris for Christmas Day, Wednesday, December 25th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:07, and it will rise tomorrow at 8:19. The Moon, 3 days past last quarter, will rise at 4:16 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted in the south-southwestern sky by 5:30 PM, about 30 minutes after sunset. It will set at 8:41 PM. Saturn will be in the south at 6 PM, way above the bright star Fomalhaut. Jupiter is low in the east-northeast, about the same time Venus is first spotted. It will be a good object for the small telescope about an hour later. Mars, rises tonight at 7:44, It will appear above the Moon in the evening. Mars is still considered a morning planet since it is still up at sunrise. By 6:00 AM tomorrow Jupiter will be low in the west-northwest, to the right of the setting Orion, while reddish Mars will be high in the west-southwest.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

This is a 6 PM planet panorama. Venus is in the southwest, Saturn is in the south, and Jupiter is rising in the east. Mars will rise shortly. Click or tap on the image to enlarge it. Created using Stellarium.

*Looking eastward at 9:00 PM at Jupiter and Mars among the rising winter constellations. Created using Stellarium.*

*The Moon as it might appear through a small telescope tomorrow morning, December 26, 2024. Selected features are labeled. Created using Stellarium, LibreOffice draw, and GIMP.*

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mars, Moon, Saturn, Venus

Ephemeris: 12/18/2024 – Taking our weekly look at the whereabouts of the naked-eye planets

December 18, 2024 bobmoler Comments off

This is Ephemeris for Wednesday, December 18th. Today the Sun will be up for 8 hours and 48 minutes, setting at 5:03, and it will rise tomorrow at 8:16. The Moon, 3 days past full, will rise at 8:36 this evening.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

This is what I call my 8:00 PM planet panorama. Venus is setting the southwest Saturn heading downwards in the southwest, Jupiter high in the east and Mars just rising in the east northeast. The waning gibbous Moon will rise shortly, trailing Mars. The only thing we’re really missing is Mercury which is close to the Sun in the morning sky. Click or tap on the image to enlarge it. Created using Stellarium.

*The Moon as it might appear through a small telescope 10 PM tonight, December 18, 2024. Selected features are labeled. Created using Stellarium, LibreOffice draw, and GIMP.*

The planet Mercury should be seen low in the southeast by 7:30 AM, tomorrow morning December 19, 2024. Created using Stellarium.

Telescopic Venus, Saturn, Jupiter and Mars (north up) as they would be seen in a small telescope with the same magnification. All the planets are shown for tonight, Jupiter specifically for 9 PM, December 18, 2024. Apparent diameters: Venus 19.7″, 61.1% illuminated; Saturn 16.9″, its rings 39.4″, 4.7 degrees from edge on (closing); Jupiter 47.9″; Mars, 13.3″, 96.3% illuminated. Saturn’s rings are actually much brighter than depicted here. Planetary surface detail is more subtle than shown here. 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 December 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, December 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.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mars, Mercury, Moon, Saturn, Venus

Ephemeris: 12/11/2024 – Where are the naked-eye planets this week?

December 11, 2024 bobmoler Comments off

This is Ephemeris for Wednesday, December 11th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:02, and it will rise tomorrow at 8:11. The Moon, 3 days past first quarter, will set at 5:00 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted in the south-southwestern sky by 5:30 PM, about 30 minutes after sunset. It will set at 8:25 PM. Saturn will be in the south at 6 PM, way above the bright star Fomalhaut. Jupiter is low in the east-northeast, about the same time as when Venus is first spotted. It will be a good object for the small telescope about an hour later. Mars, rises tonight at 8:17, Mars is still considered a morning planet since it is still up at sunrise. By 6:00 AM tomorrow Jupiter will be low in the west-northwest, to the right of the setting Orion, while reddish Mars will be high in the west-southwest.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

*Venus, Saturn, Jupiter, and the Moon as they would appear about 6 this evening in this panorama view fron east-northeast to southwest. Created using Stellarium.*

*The Moon tonight as it might appear in a small telescope. Selected features ae labeled. Created using Stellarium, LibreOffice Draw, and GIMP.*

*Jupiter with Mars rising in the east-noprtheast at 9:00 PM with Orion also rising. Created using Stellarium.*

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: Jupiter, Mars, Moon, Saturn, Venus

Ephemeris: 12/04/2024 – Checking where the naked-eye planets are now

December 4, 2024 bobmoler Comments off

This is Ephemeris for Wednesday, December 4th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:02, and it will rise tomorrow at 8:04. The Moon, 3 days past new, will set at 7:59 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted low in the south-southwestern sky by 5:30 PM, about 30 minutes after sunset. It appears above the Moon tonight, and will set at 8:09 PM. Saturn will be in the south-southeast at 6 PM. Jupiter will rise at 5:09 PM in the east-northeast, and be a good object for the small telescope about an hour later. Mars, rises tonight at 8:47, Both Mars and Jupiter are considered morning planets, since they are still up at sunrise, though Jupiter will be an evening planet after Saturday. By 6:00 AM tomorrow Jupiter will be in the west, above and right of Orion, while reddish Mars will be high in the southwest. Jupiter and Saturn are great planets to view with a small telescope.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.