Archive
Ephemeris: 02/04/2025 – Two Moon landers currently en route
This is Bob Moler with Ephemeris for Tuesday, February 4th. Today the Sun will be up for 9 hours and 58 minutes, setting at 5:56, and it will rise tomorrow at 7:56. The Moon, 1 day before first quarter, will set at 1:55 tomorrow morning.
On January 15th a SpaceX Falcon 9 rocket launched 2 missions, at one time, to land on the Moon They will arrive at the Moon months apart. The first to attempt to land is Firefly’s Blue Ghost Lander with a mission called Ghost Riders in the Sky. It is currently spending about a month in Earth orbit before heading out to the Moon, which will take four days and spend another two weeks orbiting the Moon before attempting to land in the small area called Mare Crisium, the Sea of Crises. The second Lander by the Japanese company ispace, called Resilience, will take a more circuitous route to the moon, flying by it later this month and then coming back to the Moon several months later to enter orbit and then finally land on Mare Frigoris, the Cold Sea. So the two missions will not be active on the Moon at the same time.
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
Ephemeris: 01/06/2025 – Things that go blink in the night
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
Ephemeris: 11/08/2024 – The Jade Rabbit on the Moon
This is Bob Moler with Ephemeris for Friday, November 8th. Today the Sun will be up for 9 hours and 50 minutes, setting at 5:21, and it will rise tomorrow at 7:32. The Moon, 1 day before first quarter, will set at 11:24 this evening.
Tonight’s Moon is just a few hours before the instant of first quarter which is officially at 12:56 tomorrow morning. The ancient Chinese saw in the gray areas of the Moon, we call seas, a rabbit, a pet of Chinese moon goddess Chang’e, its name was Yutu. These have become the names of the Chinese lunar landers and rovers. The top half of that rabbit is visible in the gray areas called maria, or seas. Early telescopic astronomers thought they were actually water filled basins. It turned out to be lava plains, actually floors of huge craters, from asteroids that hit the Moon 4 billion years ago during the late heavy bombardment. The top body of the rabbit is at the top part of the moon it descends to the lower right with his head and ears. The rabbit is also known as the Jade Rabbit. The rest of him is visible when the moon is full. Yutu has a real presence on the Moon, as the names of the two Chinese rovers that landed on the Moon.
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
Ephemeris: 11/07/2024 – The Moon wobbles from Earth’s point of view
This is Ephemeris for Thursday, November 7th. Today the Sun will be up for 9 hours and 53 minutes, setting at 5:22, and it will rise tomorrow at 7:31. The Moon, 2 days before first quarter, will set at 10:08 this evening.
The nearly seven day old Moon appears very low in the southwestern sky tonight. It appears as a fat crescent. The small sea called Mare Crisium or Sea of Crises, near the west edge of the Moon is a good indicator of what we call libration, that is the Moon’s slow wobbling back and forth over the month as it orbits the Earth. One can judge the amount of libration by the distance of that small round sea from the edge of the Moon. This happens because the Moon’s rotation is steady while its orbital velocity around the Earth is not, because its orbit is slightly elliptical. So sometimes the rotation gets ahead of its revolution about the Earth, and sometimes it’s behind. Right now that libration is pushing that small sea towards the edge of the Moon.
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
Ephemeris: 09/19/2024 – The Chinese Mid-Autumn Festival
This is Ephemeris for Thursday, September 19th. Today the Sun will be up for 12 hours and 17 minutes, setting at 7:44, and it will rise tomorrow at 7:28. The Moon, 2 days past full, will rise at 8:30 this evening.
Our Harvest Moon also marks the Chinese Mid-Autumn Festival. I’ve been too busy with the lunar eclipse to cover it on Tuesday. It is to honor the Moon and the story of Chang’e a mortal woman who took an elixir and flew off to the Moon and became a goddess. Another story revolves around the Jade Rabbit pounding Medicine. I sometimes talk about the figure of a rabbit seen on the face of the Moon. He is a companion to Chang’e, and has a mortar and pestle on the Moon with him. He pounds out the medicine that makes the inhabitants of the sky immortal. The Chinese lunar probes are named Chang’e. Chang’e 3 landed on the Moon in 2013 and sent out a lunar rover named Yutu, the Jade Rabbit. They have made other landings since.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Ephemeris: 09/16/2024 – Quadruple lunar events tomorrow night!
This is Ephemeris for Monday, September 16th. Today the Sun will be up for 12 hours and 26 minutes, setting at 7:50, and it will rise tomorrow at 7:24. The Moon, 1 day before full, will set at 6:34 tomorrow morning.
Tomorrow night there will be 4 lunar events occurring at the same time. Coincidence? I think not. The Moon will be full. The other events can only occur at full moon. It’s the Harvest Moon, the closest full moon to the autumnal equinox. It also happens to be a supermoon with the Moon reaching perigee, it’s closest to the Earth of the month a few hours later. Finally, the Moon will be partially eclipsed. By 9:45 PM the Moon may appear somewhat duller to the upper left than to the lower right. This is the Moon deep inside the Earth’s outer shadow called the penumbra. The actual partial phase of the eclipse will occur from 10:13 PM to 11:16 PM with the maximum occurring at 10:44 PM. With only 8 1/2 % of the Moon’s diameter covered.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
The eclipse will be visible in whole or in part for North America except for extreme western Alaska, also South America, Europe, Africa, and Western Asia. The times in Universal Time (UT): September 18, 2024, first contact 02:13, mid-eclipse 02:44, last contact 03:15.
Ephemeris: 09/13/2024 – International Observe the Moon Night tomorrow
This is Ephemeris for Friday, September 13th. Today the Sun will be up for 12 hours and 36 minutes, setting at 7:56, and it will rise tomorrow at 7:21. The Moon, 2 days past first quarter, will set at 2:25 tomorrow morning.
Tomorrow night, if it’s clear, will be the last star party of the year at the Sleeping Bear Dunes National Lakeshore starting at 9 PM if it is clear. It coincides with the International Observe the Moon Night, which is held annually in September or October near the first quarter moon, give or take a few days. Hosting the event will be the Park Rangers and the Grand Traverse Astronomical Society. Also featured will be the planet Saturn which is exhibiting some very thin rings this year. The 2020s appears to be the decade of the Moon with the United States and its European and Canadian partners, China, Russia, and even India interested in landing instruments and people on the Moon. So far this decade only China and India have had completely successful landings of spacecraft on the Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Ephemeris: 09/12/2024 – Does the Moon have a square crater?
This is Ephemeris for Thursday, September 12th. Today the Sun will be up for 12 hours and 39 minutes, setting at 7:58, and it will rise tomorrow at 7:19. The Moon, 1 day past first quarter, will set at 1:11 tomorrow morning.
I built my first telescope in the mid 1950s from the kit. It had a 5-inch diameter mirror. Of course one of the first things I looked at was the Moon. And while familiarizing myself with the Moon’s features I noticed that around first quarter moon there was a funny little crater near the Moon’s North Pole that looked square. All the other craters were round. This one being near the North Pole was foreshortened a bit, so it’ll look rectangular. It sure had walls that looked like they were straight rather than curved. The crater’s name is Barrow. And the description I found of it said it had an interesting shape, though they didn’t mention it was square. Looking closely at it, it is squarish but in small telescopes it definitely looks like it’s a square crater. The best time to try to spot it is around first quarter moon or up to a couple of days later.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
The base imagery used for the Virtual Moon Atlas, I believe, came from the Clementine spacecraft, a joint project of NASA and the Department of Defense, which orbited the Moon for 71 days in the mid 90s and then was sent out to an asteroid. However, on the way to the asteroid a problem occurred and Clementine was “lost and gone forever”.
Ephemeris: 08/13/2024 – Antares and the Moon
This is Ephemeris for Tuesday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 1 day past first quarter, will set at 12:41 tomorrow morning.
The Moon tonight will have a companion. Just to the left of it will be a star. That star may not look very bright because it is overpowered by moonlight, but it is one of the brightest stars of the sky. It is Antares in Scorpius the scorpion, a red giant star. Every month for the last several years and for the next several years the moon will pass in front of that star. Unfortunately due to the timing and to the path of the Moon it doesn’t happen for any particular spot on the Earth very often. Tonight, as the Moon sets it will be approaching Antares but will appear about to pass below it at the time it sets. We will not be able to see the Moon actually cover or occult Antares from Northern Michigan until May 2028, nearly four years from now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 07/18/2024 The brightest spot on the Moon
This is Ephemeris for Thursday, July 18th. Today the Sun will be up for 15 hours and 7 minutes, setting at 9:22, and it will rise tomorrow at 6:15. The Moon, 3 days before full, will set at 3:40 tomorrow morning.
The moon tonight is bright. The sunrise line or terminator on the moon is crossing the large gray plain called Oceanus Procellarum, the largest of the moon’s seas. These seas were figments of the first telescopic observer’s imagination. They are really huge impact basins into which interior lava flowed. On the left side of the Moon is a bright spot in the gray expanse of Oceanus Procellarum visible in binoculars. In a telescope it is a crater called Aristarchus. It is a fairly new crater in lunar terms, probably less than a billion years old. As a rule the brighter the crater the newer it is. Aristarchus is the brightest spot on the Moon. Over the years visual astronomers have seen hazes and bright spots from time to time in and near Aristarchus.
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
Bob Moler's Ephemeris Blog 