Archive
06/09/2022 – Ephemeris – Looking at the gibbous Moon tonight
This is Bob Moler with Ephemeris for Thursday, June 9th. Today the Sun will be up for 15 hours and 29 minutes, setting at 9:27, and it will rise tomorrow at 5:57. The Moon, 2 days past first quarter, will set at 3:29 tomorrow morning.
By tonight, the gibbous moon will be quite bright. At the moon’s left edge, just coming into sunlight, will be what looks like a large half crater at the edge of the lunar sea called Mare Imbrium, the Sea of Showers. That feature is Sinus Iridium, or Bay of Rainbows. The arc of its mountainous edge is rainbow shaped, but it is as colorless as the rest of the Moon. The crater Copernicus sports few shadows and appears mostly as a bright spot surrounded by its ray system of ejecta craters that appear bright when the sun is high in their sky. At the south end of the Moon are the lunar highlands, bright, rugged and covered by large, mostly very old craters. Largest of these craters is Clavius, named for Christophorus Clavius who, working for Pope Gregory XIII, devised the Gregorian Calendar we use today.
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
Binocular Moon as it might appear tonight, June 9, 2022. Below, we’ll look closer to the terminator area of the Moon. Created using Virtual Moon Atlas.
Northern gibbous Moon terminator area with labels for some prominent features. Created using Virtual Moon Atlas, LibreOffice and GIMP.
Southern gibbous Moon terminator area with labels for some prominent features. Created using Virtual Moon Atlas, LibreOffice and GIMP.
Translations
Mare Frigoris – Sea of Cold
Mare Imbrium – Sea of Showers
Mare Nubium – Sea of Clouds
Montes Alpes – Alps Mountains
Montes Appinenninus – Apennines Mountains
Sinus Iridium – Bay of Rainbows
03/11/2022 – Ephemeris – Looking at the northern part of the Moon and the crater Plato
This is Ephemeris for Friday, March 11th. Today the Sun will be up for 11 hours and 41 minutes, setting at 6:43, and it will rise tomorrow at 7:00. The Moon, 1 day past first quarter, will set at 4:18 tomorrow morning.
As the Moon moves around the Earth, now one day past first quarter, more of it is revealed in sunlight. The top or north part of the moon is of interest now. The second-largest lunar sea, Mare Imbrium, or Sea of Showers, is now half illuminated by the advancing terminator, the sunrise line. That can be seen with the naked eye. With binoculars, in the mountains north or above Imbrium can be found the flat floored crater or walled plain called Plato. This crater is situated in the lunar Alps. Mountains on the Moon are named after their earthly counterparts. Visible in telescopes now will be the Alpine Valley cutting through the Alps just to the right of Plato. Each night from new to full, more of the Moon’s features are revealed near the terminator.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.
Addendum
The Moon tonight, a day past first quarter, March 11, 2022, outlining the Mare Imbrium, crater Plato area, which is seen in detail below. Created using Virtual Lunar Atlas.
The Moon tonight, March 11, 2022, highlighting the crater Plato and lunar Alps. The Alpine Valley (Vallis Alpes), lies under the caption “Alpes” for the mountains. One of cool things to watch when the terminator is situated just right is to watch the shadows of the mountains retreat across Plato’s crater floor as the Sun rises. The shadows of the peaks appear very jagged as they retreat. Created using Virtual Lunar Atlas.
03/23/2021 – Ephemeris – The Moon tonight: Bay of Rainbows
This is Bob Moler with Ephemeris for Tuesday, March 23rd. Today the Sun will be up for 12 hours and 19 minutes, setting at 7:59, and it will rise tomorrow at 7:37. The Moon, 2 days past first quarter, will set at 5:50 tomorrow morning.
A look at the Moon tonight will reveal that the sunrise line, or terminator has almost completely revealed the large Sea of Showers or Mare Imbrium to the upper left of the center of the gibbous disk. At the extreme upper left nearly completely in sunlight a very popular feature, the Bay of Rainbows or Sinus Iridium. It’s a colorful name for something that’s as gray as the rest of the Moon. It looks like a bay off of Imbrium, and has an arch like a rainbow. Its arch is the Jura Mountains, which jut into Mare Imbrium at Cape Heraclide, just catching sunlight, and Cape Laplace farther into morning. What’s cool is catching it as the sunlight is hitting the mountains while the convex floor, following the Moon’s curvature is only partially illuminated.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon a little before how it will appear tonight highlighting Sinus Iridium. By tonight the floor of Sinus Iridium should be pretty much sunlit, and the Jura mountains completely lit. Created using Virtual Moon Atlas.
Sinus Iridium at sunrise. Photo by “Seb2003” on http://forums.futura-sciences.com/materiel-astronomique-photos-damateurs/5809-images-de-lune.html.
01/26/2018 – Ephemeris – The Moon tonight: The Bay of Rainbows
Ephemeris for Friday, January 26th. The Sun will rise at 8:08. It’ll be up for 9 hours and 34 minutes, setting at 5:43. The Moon, 2 days past first quarter, will set at 3:59 tomorrow morning.
A look at the Moon tonight will reveal that the sunrise line, or terminator has almost completely revealed the large sea of Showers or Mare Imbrium to the upper left of center of the gibbous disk. At the extreme upper left straddling the terminator is one of my favorite features, the Bay of Rainbows or Sinus Iridium. It’s a colorful name for something that’s as gray as the rest of the Moon. It looks like a bay off of Imbrium, and has an arch like a rainbow. It’s arch is the Jura Mountains, which jut into Mare Imbrium at Cape Heraclide, just catching sunlight, and Cape Laplace farther into morning. What’s cool is catching it as the sunlight is hitting the mountains while the convex floor, following the Moon’s curvature is only partially illuminated.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 8 p.m. January 26, 2018 highlighting Sinus Iridium. Created using Virtual Moon Atlas.
Sinus Iridium photographed by the Lunar Reconnaissance Orbiter as texture mapped on the globe of the Virtual Moon Atlas.
Sinus Iridium at sunrise. Photo by “Seb2003” on http://forums.futura-sciences.com/materiel-astronomique-photos-damateurs/5809-images-de-lune.html.
01/25/2018 – Ephemeris – The Moon tonight: Copernicus on the terminator
Ephemeris for Thursday, January 25th. The Sun will rise at 8:09. It’ll be up for 9 hours and 32 minutes, setting at 5:41. The Moon, 1 day past first quarter, will set at 2:48 tomorrow morning.
Let’s take a look at our slightly gibbous moon, just a day past first quarter with binoculars or a small telescope. The terminator, in this case the sunrise line will appear to cross the crater Copernicus to the right of the Moon’s center if you’re viewing it right side up. To the North across the Sea of Showers, or Mare Imbrium is the large flat floored crater Plato. South of Copernicus is a recently named sea, Mare Cognitum, the Known Sea, after the first successful close photography by the Ranger 7 spacecraft in 1964. South of the is Mare Nubium, the Sea of Clouds. South of that are the lunar highlands with the stark crater Tycho and the huge crater Clavius with an arc of craters of decreasing size within it.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The waxing gibbous Moon tonight at 8 p.m., January 25, 2018. Created using Virtual Moon Atlas.
The crater Copernicus. Credit: NASA/GSFC/Arizona State University.
The Lunar highlands near the crater Tycho showing a surface saturated with craters. Credit: Virtual Moon Atlas with the texture from NASA’s Lunar Reconnaissance Orbiter. The lunar phase was omitted.
Clavius as photographed by one of the Lunar Orbiter spacecraft in the 1960s From Digital Lunar Orbital Photographic Atlas. Credit Jeff Gillis, Lunar and Planetary Institute.
03/07/2017 – Ephemeris – The Moon tonight – the crater Copernicus
Ephemeris for Tuesday, March 7th. The Sun will rise at 7:08. It’ll be up for 11 hours and 29 minutes, setting at 6:38. The Moon, 2 days past first quarter, will set at 4:39 tomorrow morning.
Looking at the Moon tonight the brightest feature on the left side of the moon is the big splash mark left by the impact that created the crater Copernicus. The proper term is ejecta blanket that can be noticed by the naked eye or binoculars. Although it is most visible during full moon, because it is really made of small craters that are most visible when we see them from the direction of the Sun, so they are not shadow filled and brighter than normal. Copernicus is on the south edge of a great lava plain called Mare Imbrium, the Sea of Showers. There’s a large crater on the north edge named after the Greek philosopher Plato. At the upper left edge is the Laplace promontory the point of the Bay of Rainbows to be revealed tomorrow night.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon featuring Copernicus, Plato, Laplace Promontory and Mare Imbrium at 9 p.m., March 7, 2017. Created using Virtual Moon Atlas.
10/11/2016 – Ephemeris – Looking at the Moon tonight
Ephemeris for Tuesday, October 11th. The Sun will rise at 7:53. It’ll be up for 11 hours and 10 minutes, setting at 7:04. The Moon, 2 days past first quarter, will set at 3:26 tomorrow morning.
We looked at the Moon in the last program, now 24 hours later the sunrise terminator has moved farther west, our east uncovering more landscape. The Moon rotates once in about 29 ½ days in relation with the Sun. This is the same time it orbits the Earth from new Moon to the next. We call that a lunation or lunar month. Near the upper left corner of the Moon is what looks like a half crater. It’s called Sinus Iridium, the Bay of Rainbows. It’s at the edge of Mare Imbrium or Sea of Showers. To the south cut by the terminator is Oceanus Procellarum, the flat Ocean of Storms. South of that is the small Mare Humorum, the Sea of Vapors. Between then is a distinctive crater Gassendi. South of all that is the odd shaped crater Schiller.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 9 p.m. October 11, 2016. Created using Virtual Moon Atlas.
Sinus Iridium photographed by the Lunar Reconnaissance Orbiter as texture mapped on the globe of the Virtual Moon Atlas.
The crater Gassendi from Apollo 16 – NASA
The craters Schickard and Schiller as seen from above from the Lunar Reconnaissance Orbiter. The Sun will start to rise on Schickard tomorrow night. Credit NASA from Virtual Moon Atlas.
10/10/2016 – Ephemeris – Checking out the gibbous Moon tonight
Ephemeris for Indigenous Peoples Day*, Monday, October 10th. The Sun will rise at 7:52. It’ll be up for 11 hours and 13 minutes, setting at 7:06. The Moon, 1 day past first quarter, will set at 2:20 tomorrow morning.
The Moon is beginning to dominate the evening sky. So it’s time to get out that telescope or powerful binoculars. The terminator which now is the sunrise line will be cutting through the Sea of Showers, also known as Mare Imbrium. Just south of it is the large crater Copernicus, 56 miles (93 km) in diameter. Copernicus, near the Moon’s equator hit a flat lunar sea, so it’s quite conspicuous. Another crater near the Moon’s south pole is conspicuous because it’s so big. It’s Clavius, with an arc of diminishing sized craters within. It is 136 miles (225 km) in diameter. In the book and movie 2001: A Space Odyssey, it is the location of the US Moon Base, with the monolith in the distinctive crater Tycho north of it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 9 p.m. October 10, 2016, with the landmarks described in the text above,
* Indigenous Peoples Day – This is officially the Columbus Day holiday in the United States, which commemorates the landing of Christopher Columbus possibly on Plana Cay, which he named San Salvador. While in his four voyages he visited some Caribbean islands, Central and South America. He never made it to North America. Columbus was appointed the Viceroy and Governor of the Indies. He was accused of torture and other crimes. And the treatment of the Indigenous peoples as been horrific then and ever since, so pardon them if they don’t celebrate Columbus Day. This person of European ancestry tends to agree with them.
12/18/2015 – Ephemeris – The Moon at first quarter tonight
Ephemeris for Friday, December 18th. The Sun will rise at 8:15. It’ll be up for 8 hours and 48 minutes, setting at 5:03. The Moon, at first quarter today, will set at 1:17 tomorrow morning.
By the time we see the moon tonight it will be at least 8 hours since the Moon passed the first quarter point and it’s terminator or sunrise line will appear slightly bowed. This time, since I can only point out a few features at a time, I’d like to point out three craters on the upper, north portion of the moon. They may be too small for binoculars, but fine for small telescopes. They make a nearly right triangle in Mare Imbrium, the Sea of Showers near the terminator. The largest is Archimedes, named for the 3rd century BC Greek mathematician, and inventor. The northern crater is Aristillus, named after a 3rd century BC astronomer, The other crater is Autolycus, named for a 4th century BC Greek astronomer.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The first quarter Moon on December 18 at 9 p.m. EST. Highlighted are the trio of craters of which Archimedes is the largest. Created using Virtual Moon Atlas.
Other features visible are the crater Plato, the Alpine Valley, the crater Alphonsus, which I’ve covered in the past. Search on them for their location and more information.
11/19/2015 – Ephemeris – The no longer quite first quarter Moon tonight
Ephemeris for Thursday, November 19th. The Sun will rise at 7:44. It’ll be up for 9 hours and 26 minutes, setting at 5:11. The Moon, at first quarter today, will set at 1:06 tomorrow morning.
The Moon actually was at first quarter at 1:27 (6:47 UT) this morning. By this evening, when it’s out the terminator, the sunrise line, on the Moon will be curved giving the it a definite gibbous appearance. The upside down rabbit image in the Moon’s dark seas on the illuminated right half can be seen. In a telescope or even powerful binoculars at 9 p.m. the Terminator cuts the southern crater Tycho in half. The large crater Clavius south of it is just catching the morning Sun. To the north the sunrise line cuts the large Mare Imbrium or Sea of Showers in half. In the mountains on the north shore of Imbrium the large walled plain, really a crater, Plato can be seen. Pan near the terminator in the south and the Straight Wall might be spotted as a long shadow.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 9 p.m. EST November 19, 2015. (2 hr UT November 20) Created using Virtual Moon Atlas.
Closeup chart of the Straight Wall.
Bob Moler's Ephemeris Blog 