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Archive for May, 2026

Ephemeris: 05/29/2026 – NASA’s second moon program – soft landers

May 29, 2026 Comments off

This is Ephemeris for Friday, May 29th. Today the Sun will be up for 15 hours and 16 minutes, setting at 9:18, and it will rise tomorrow at 6:01. The Moon, 2 days before full, will set at 5:01 tomorrow morning.

The United States second unmanned moon program in the 1960s was the Surveyor program, to soft land spacecraft on the moon. This was the Surveyor program, which launched 5 Surveyor spacecraft to the moon from 1966 through 1968, three of which were successful, including the very first one. It showed that the moon’s surface was solid enough to support spacecraft landings. There was some speculation earlier that moon dust would be electrostatically charged and suspended above the solid surface of the moon preventing a landing on the surface. The moon’s surface proved to be solid enough, paving the way for the Apollo landings to come. Apollo 12 landed near Surveyor 3 and took a souvenir back to earth, the camera.

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

Surveyor program
Surveyor 3, visited by astronaut Pete Conrad during the Apollo 12 mission. Credit: NASA / Alan Bean.
Categories: Ephemeris Program, NASA, Space History Tags:

Ephemeris: 05/28/2026 – NASA’s first Moon program

May 28, 2026 Comments off

This is Ephemeris for Thursday, May 28th. Today the Sun will be up for 15 hours and 15 minutes, setting at 9:17, and it will rise tomorrow at 6:02. The Moon, 3 days before full, will set at 4:32 tomorrow morning.

The United States first lunar mission to the moon was the Ranger Program of moon impactors, to televise pictures all the way to impact to see what the moon looked like up close and personal, so to speak. The program actually started before President Kennedy announced plans to send humans to the moon, although the first launch was made several months after that announcement. The program consisted of nine launches of three different variations of the spacecraft. The first two launches failed Then in the next four launches, the spacecraft either missed the moon or were dead on arrival. However, the last three were successful, showing that the moon was indeed mostly smooth enough to land a spacecraft.

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

Ranger Block III Spacecraft diagram.
Ranger Block III Spacecraft diagram. Credit NASA/JPL.
Alphonsus crater from Ranger 9.
Alphonsus crater from Ranger 9. The crater is 73 miles, 118 km, in diameter. Credit: NASA/JPL.
Ranger Image 2
Ranger 9 Image of Alphonsus #2. Credit NASA.
Ranger Inage 3
Ranger 9 Image of Alphonsus #3. Credit NASA.

Categories: Ephemeris Program, Space History, Space Race Tags: , ,

Ephemeris: 05/27/2026 – Taking our weekly look at the whereabouts of the naked-eye planets

May 27, 2026 Comments off

This is Bob Moler with Ephemeris for Wednesday, May 27th. Today the Sun will be up for 15 hours and 13 minutes, setting at 9:17, and it will rise tomorrow at 6:02. The Moon, halfway from first quarter to full, will set at 4:08 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. By 10 PM tonight, about 40 minutes after sunset, Venus may be seen in the western sky. A telescope will show a very tiny disc on Venus, because it is still pretty much beyond the Sun, 120 million miles (193 million km) away from us. Over the next 5 months it will be moving closer to us and becoming much larger. Jupiter is the second-brightest star-like object in the western sky seen before 10 PM. It is above and left of Venus tonight. Venus will set at 12:04 AM, while Jupiter will hold out until 12:41 AM. Saturn rises in the east at 3:52 AM, followed by dimmer Mars at 4:42 AM.

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

Jupiter and Venus in the western sky, at 10 PM tonight, May 27, 2026. Jupiter and Venus are appearing to approach each other. They will be in conjunction on the evening of June 8th.
Jupiter and Venus at 10 PM tonight, May 27, 2026. Jupiter and Venus are appearing to approach each other. They will be in conjunction on the evening of June 8th. Created using Stellarium.
The Moon, 4 days after first quarter, as seen at 10 PM tonight, May 27, 2026. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP
Saturn and Mars seen low in the east at 5 AM May 28, 2026.
Saturn and Mars at 5 AM May 28, 2026. Created using Stellarium.
Telescopic Venus and Jupiter at 10 PM on the 27th, and Saturn at 5 AM on the 28th.
Telescopic Venus and Jupiter at 10 PM on the 27th, and Saturn at 5 AM on the 28th (north up), as they would be seen in a small telescope with the same magnification. Venus’ apparent diameter will be 13.0″, and be 80.7% illuminated. It’s on the far side of the Sun. Jupiter will be 33.4″ in diameter, with its moons shown for the time listed. Saturn will be 17.0″ in diameter, and its rings extend to 38.7″ and are tilted 8.2º to our view. Mars will appear 4.3″ in diameter. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets at sunset and sunrise on a single night, starting with sunset on the right on May 27, 2026. The night ends on the left with sunrise on the 28th.
The naked-eye planets at sunset and sunrise on a single night, starting with sunset on the right on May 27, 2026. The night ends on the left with sunrise on the 28th. 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, May 27 and 28th, 2026
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, May 27 and 28th, 2026. Some of the columns are self-explanatory, others are 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 Tags: , , , , ,

Ephemeris: 05/26/2026 – The Soviet Union’s Luna 3 provided first look at the far side of the Moon

May 26, 2026 Comments off

This is Bob Moler with Ephemeris for Tuesday, May 26th. Today the Sun will be up for 15 hours and 11 minutes, setting at 9:16, and it will rise tomorrow at 6:03. The Moon, 3 days past first quarter, will set at 3:48 tomorrow morning.

The space race with the Soviet Union started with the launch of Sputnik one in October 1957. The Soviets won the early milestones of the race, including less than two years after Sputnik 1, a flyby of Luna 3 around the moon, and taking the first photographs of the far side. Back then before CCDs, the best quality images from space were photographed onto film and then developed, then scanned on the satellite and the data is sent down to the earth. The images were rather crude and grainy. I was a senior in high school at the time and as interested in astronomy as I am today. We thought that the Far Side of the moon would be more of the same. The Far Side was completely different.

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

Comparing the Luna 3 photograph with a NASA Lunar Reconnaissance Orbiter composite. Labels are mine.

Categories: Space History, Space Race Tags: , ,

Ephemeris: 05/25/2026 – Remembering the fallen astronauts also

May 25, 2026 Comments off

This is Ephemeris for Memorial Day, Monday, May 25th. Today the Sun will be up for 15 hours and 10 minutes, setting at 9:15, and it will rise tomorrow at 6:04. The Moon, 2 days past first quarter, will set at 3:30 tomorrow morning.

Today we pause to remember those who gave their lives for our country. For purposes of this program that includes those courageous enough to sit on top of or beside a million pounds of explosives to be launched into space. From the three astronauts who died in the Apollo one file in 1967, the explosion of the Space Shuttle Challenger in 1986, to the disintegration of the Columbia in 2003, 17 Americans and other nationals have died in NASA space accidents. The Russians too have lost cosmonauts in the exploration of space. Brothers and sisters in the quest for knowledge and to expand the horizons of human habitation.  Per aspera, ad astra, Through difficulties to the stars

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

Apollo 1 crew: Gus Grissom, Ed White and Roger Chaffee
The Apollo 1 crew: Gus Grissom, Ed White and Roger Chaffee. They perished in a capsule fire during a ground test January 27, 1967. Credit: NASA.
Space shuttle STS-51L Crew- Ellison S. Onizuka, Christa McAuliffe, Gregory B. Jarvis, Judith A. Resnik, Michael J. Smith, Francis R. Scobee, and Ronald E. McNair
STS-51L Crew Back Row: Mission Specialist Ellison S. Onizuka, Payload Specialists Christa McAuliffe and Gregory B. Jarvis, Mission Specialist Judith A. Resnik, Front Row: Pilot Michael J. Smith, Commander Francis R. Scobee, Mission Specialist Ronald E. McNair. They died during liftoff on Januaty 28, 1986. Credit: NASA.
The crew of the final ill-fated flight of the Space Shuttle Columbia, mission STS-107
The crew of the final ill-fated flight of the Space Shuttle Columbia, mission STS-107. From left to right are mission specialist David Brown, commander Rick Husband, mission specialist Laurel Clark, mission specialist Kalpana Chawla, mission specialist Michael Anderson, pilot William McCool, and Israeli payload specialist Ilan Ramon. All were killed when the shuttle disintegrated over Texas on February 1, 2003.

Categories: Ephemeris Program, History, NASA, Space Flight, Space History

Ephemeris: 05/22/2026 – Uranus has rings, like Saturn

May 22, 2026 Comments off

This is Bob Moler with Ephemeris for Friday, May 22nd. Today the Sun will be up for 15 hours and 4 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon, 1 day before first quarter, will set at 2:35 tomorrow morning.

Today, the planet Uranus is in conjunction with the Sun. I don’t talk about Uranus that much, because it can’t be spotted in the sky with the naked eye. However, the James Webb Space Telescope observed it, and gave our clearest view of the planet since Voyager 2 flew past it in January 1986. Uranus has a system of rings, which were discovered in March 1977. Though not visible, they blocked the light of a star. Astronomers at the time were trying to get a more accurate diameter of the planet by timing the disappearance of a star behind the planet. Extra short dips in brightness before and after the main occultation revealed the existence of the rings. Uranus also has an extreme axial tilt of 98 degrees.

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

Plot of the occultation of star SAO 158687 by 5 thin Uranian rings before and after the occultation of the star by the planet.
Plot of the occultation of star SAO 158687 by 5 thin Uranian rings before and after the occultation of the star by the planet. The observation was performed by the NASA’s Kuiper Airborne Observatory on March 10, 1977. Credit: NASA/JPL.
Image of a portion of a Uranian ring by the Voyager 2 spacecraft in a time exposure.
Image of a portion of a Uranian ring by the Voyager 2 spacecraft in a time exposure to bring out the dim ring, causing the stars to trail behind it. Credit NASA/JPL.
Uranus and rings from the JWST
Uranus and its rings as photographed by the James Webb Space Telescope. The rings are much brighter in the infrared. Credit: NASA\CSA\ESA.
Categories: Ephemeris Program, NASA, Planetary Science

Ephemeris: 05/21/2026 – The man who first mapped the Moon

May 21, 2026 Comments off

This is Ephemeris for Thursday, May 21st. Today the Sun will be up for 15 hours and 2 minutes, setting at 9:11, and it will rise tomorrow at 6:07. The Moon, 2 days before first quarter, will set at 2:11 tomorrow morning.

Ever wonder where the names of the features of the Moon come from? Most of the large features on the Moon were named by Giovanni Battista Riccioli, a Jesuit priest of the 17th century. He created the first accurate map of the Moon in 1651, and he named the features he drew, including the Sea of Tranquility (Mare Tranquillitatis), the craters Tycho, Plato, Clavius and many others that I talk about. Even though he professed the Earth centered universe, he gave the heliocentrists Copernicus, Kepler and Aristarchus prominent craters, but in the Ocean of Storms, Oceanus Procellarum, denoting the controversy of the day. Riccioli’s nomenclature became the standard for the Moon and other planets and moons.

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

Giovanni Battista Riccioli portrait.
Giovanni Battista Riccioli
Riccioli’s 1651 map of the Moon with many features labeled.
Riccioli’s 1651 map of the Moon with many features labeled. Click or tap on the image to enlarge it.
Categories: Astronomical History, Ephemeris Program, The Moon Tags:

Ephemeris: 05/20/2026 – Taking our weekly look at the whereabouts of the naked-eye planets

May 20, 2026 Comments off

This is Ephemeris for Wednesday, May 20th. Today the Sun will be up for 15 hours exactly, setting at 9:09, and it will rise tomorrow at 6:08. The Moon, 3 days before first quarter, will set at 1:41 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. By 9:30 PM tonight, about 20 minutes after sunset, Venus may be seen in the western sky. A telescope will show a very tiny disc on Venus, because it is still pretty much beyond the Sun, 124 million miles (199 million kilometers) away from us. Over the next 5 months it will be moving closer to us and becoming much larger. Jupiter is the second-brightest star-like object in the western sky seen before 10 PM. It is below and right of the Moon tonight. Venus will set at 11:53 PM, while Jupiter will hold out until 1:01 AM. Saturn may be first glimpsed just after it rises in the east at 4:18 AM, before morning twilight overwhelms it later on.

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

Jupiter, Venus and the Moon itself at twice actual size at 10 PM tonight, May 20, 2026. Jupiter and Venus are appearing to approach each other. They will be in conjunction on the evening of June 8th.
Jupiter, Venus and the Moon, itself at twice actual size, at 10 PM tonight, May 20, 2026. Jupiter and Venus are appearing to approach each other. They will be in conjunction on the evening of June 8th. Created using Stellarium.
The Moon, 4 days after new, as seen at 10 PM tonight, May 20, 2026. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Saturn and Mars low in the east at 5:15 AM May 21, 2026. Mars may not actually be visible, being too low and faint.
Saturn and Mars at 5:15 AM May 21, 2026. Mars may not actually be visible, being too low and faint. Created using Stellarium.
Telescopic Venus and Jupiter at 10 PM on the 20th, and Saturn at 5:15 AM on the 21st (north up), as they would be seen in a small telescope with the same magnification.
Telescopic Venus and Jupiter at 10 PM on the 20th, and Saturn at 5:15 AM on the 21st (north up), as they would be seen in a small telescope with the same magnification. Venus’ apparent diameter will be 13.0″, and be 82.8% illuminated. It’s on the far side of the Sun. Jupiter will be 33.9″ in diameter, with its moons shown for the time listed. Saturn will be 16.4″ in diameter, and its rings extend to 38.3″ and are tilted 8º to our view. Mars will appear 4.2″ in diameter. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets at sunset and sunrise on a single night, starting with sunset on the right on May 20, 2026. The night ends on the left with sunrise on the 21st.
The naked-eye planets at sunset and sunrise on a single night, starting with sunset on the right on May 20, 2026. The night ends on the left with sunrise on the 21st. 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, May 20 and 21st, 2026. Some of the columns are self-explanatory, others are 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 Tags: , , , , ,

Ephemeris: 05/19/2026 – The Greeks discovered that the Earth was round and determined the Moon’s distance

May 19, 2026 Comments off

This is Bob Moler with Ephemeris for Tuesday, May 19th. Today the Sun will be up for 14 hours and 58 minutes, setting at 9:08, and it will rise tomorrow at 6:09. The Moon, 3 days past new, will set at 1:01 tomorrow morning.

The Ancient Greeks used lunar eclipses to determine that Earth is a sphere, and worked on determining the distance to the Moon. From ancient times, the Greeks knew that an eclipse of the Moon was caused by the Earth’s shadow falling on the Moon. Since the Earth’s shadow was always circular, no matter where the Moon was in the sky during an eclipse, the Earth must be a sphere since that’s the only three-dimensional body that always casts a circular shadow. They also used the size of the Earth’s shadow to estimate the distance to the Moon. The lunar distance, on average, is 60.8 times the Earth’s radius away. The first estimates were about one third of that. Hipparchus in the 2nd century BC got much closer at 68 Earth radii.

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

Partial Lunar Eclipse showing arc of the Earth's shadow
Partial Lunar Eclipse showing circular arc of the Earth’s shadow. Taken by me from the Veen Observatory of the Grand Rapids Amateur Astronomical Association at 04:15 UT August 17, 1970.
The partially eclipsed Moon setting through a thin cloud and the neighbor kid’s swing set.
The partially eclipsed Moon setting through a thin cloud and the neighbor kid’s swing set at 7:09 AM EDT April 4, 2015. Sunrise that morning was at 7:18 AM. Taken with a smartphone through 10X50 binoculars. If the Earth were pizza shaped, it would cast a shadow like the cloud in the image.
Earth and Moon size and distance to scale.
Earth and Moon size and distance to scale. Modified from the original GIF animation by the author.

Categories: Astronomical History, Ephemeris Program, The Earth, The Moon Tags:

Ephemeris: 05/18/2026 – Earth shines on the Moon

May 18, 2026 Comments off

This is Bob Moler with Ephemeris for Monday, May 18th. Today the Sun will be up for 14 hours and 56 minutes, setting at 9:07, and it will rise tomorrow at 6:10. The Moon, 2 days past new, will set at 12:07 tomorrow morning.

The Moon tonight will appear as a thin sliver, with Venus below and left of it. However, if as you look at the Moon closely tonight you may have the funny feeling that the whole moon is actually visible, you would be right. It’s easily confirmed with a pair of binoculars or a small telescope. What is illuminating the dark part of the Moon is earthshine. The Earth is big and bright in the Moon’s sky, as a fat waning gibbous orb from its vantage point. From the Moon the Earth has the opposite phase that we see of the Moon from the Earth. The effect used to be called by the term “Old moon in the new moon’s arms”. The effect was first explained by Leonardo da Vinci some 500 years ago. The effect will disappear in a few days as the Moon gets brighter and the Earth less so in the Moon’s sky. Earthshine will appear again when the Moon appears as a waning crescent in the morning. But not many of us are up to see it at that hour.

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

Earthshine by Bob Moler
Earthshine shown on a waxing crescent Moon taken by me back in the days before digital cameras. The bright crescent had to be overexposed to bring out the night side being illuminated by the Earth. The over exposure crescent part caused it to “bloom”, expanding it to adjacent parts of the image.
During the solar eclipse caused by the Moon, while Integrity and the crew were again in sight of the Earth, but not of the Sun, the Earth’s reflected sunlight illuminates the upper left part of the Moon. Credit: NASA/Artemis 2 crew.
The first solar eclipse experienced by the Artemis 2 crew, caused by the Earth. In this longer exposure, the night side of the earth is flooded by moonshine from the nearly full Moon in the Earth’s sky. What surprises is the color. On Earth the world appears in shades of gray under the light of the nearly full moon. The reason is the low light level. Our eyes have two kinds of photoreceptors: cones and rods. The cone s work best in bright light. They detect colors. Rods, work at low light levels, sacrificing color detection. Credit: NASA/Artemis 2 crew.

Categories: Artemis Program, Eclipses, Ephemeris Program Tags: ,