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Ephemeris: 03/26/2024 – The dimmest constellation of the Zodiac is Cancer the crab

March 26, 2024 Comments off

This is Ephemeris for Tuesday, March 26th. Today the Sun will be up for 12 hours and 29 minutes, setting at 8:03, and it will rise tomorrow at 7:31. The Moon, 1 day past full, will rise at 9:44 this evening.

The dimmest constellation of the Zodiac is Cancer the crab. It is located high in the southeast at 9 PM between the backwards question mark that is the front of Leo the lion towards the lower left and Castor and Pollux of Gemini to the upper right. Its claim to more modern astronomical fame is the star cluster within it called the Beehive Cluster also known in ancient times as Praesepe the manger which looks like a fuzzy spot to the naked eye. In binoculars or a small telescope it shows up as a rather sparse open cluster of stars and to me the whole cluster appears somewhat triangular like an old-fashioned beehive. The Beehive cluster is relatively close to us at about 610 light years away.

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

Cancer the crab finder
Cancer the crab is located in the southeastern sky between Leo the lion to the lower left and Castor and Pollux of Gemini to the upper right. Created using Stellarium.
Beehive Cluster finder
Finding the Beehive Cluster is fairly easy once you find Cancer. It looks like a fuzzy spot to the naked eye as Praesepe the manger. But in binoculars the star cluster shows as individual stars and a telescope will pick up even more stars in this cluster. It is also known as M 44. Created using Stellarium, LibreOffice and GIMP.

Ephemeris: 03/25/2024 – Your subsequent opportunities for total solar eclipses in the U.S. if you miss the April 8th one

March 25, 2024 Comments off

This is Ephemeris for Monday, March 25th. Today the Sun will be up for 12 hours and 26 minutes, setting at 8:02, and it will rise tomorrow at 7:33. The Moon, at full today, will rise at 8:39 this evening.

The Moon was officially full at 3:00 this morning. At that time it was in a penumbral eclipse. If you didn’t see it you didn’t miss much. Deep penumbral eclipses only show that the moon has a proverbial 5 o’clock shadow. This means that for the next new moon we’ll have a total solar eclipse. It’s in exactly 2 weeks. The eclipse totality path, in the United States, will run from Texas to Maine, and through Indiana and northwestern Ohio. The next total solar eclipse for the U.S. will occur in 2044, a sunset eclipse visible from parts of Montana and North Dakota. The next great eclipse for North America and the U.S. will be on August 12th of 2045, twenty years from now. The totality path will pass from Northern California all the way through to Florida.

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

The total solar eclipse of August 23, 2044
The eclipse will be visible in the area underneath the red lines. Within the dark blue lines is where totality will be visible. In United States that only includes parts of North Dakota and Montana at sunset. the funny three line teardrop in the right is where the eclipse will be in progress at sunset . Adapted from an eclipse map from NASA/GSFC, Fred Espenak.
The total solar eclipse of August 12, 2045
This is the next Great American Eclipse after the April 8th eclipse . The path runs from Northern California to Florida . It is generally parallel to and south of the eclipse path of the August 21st 2017 eclipse. Adapted from an eclipse map from NASA/GSFC, Fred Espenak.

Ephemeris: 03/22/2024 – There will be a penumbral eclipse of the Moon Monday morning

March 22, 2024 Comments off

This is Ephemeris for Friday, March 22nd. Today the Sun will be up for 12 hours and 17 minutes, setting at 7:58, and it will rise tomorrow at 7:39. The Moon, 3 days before full, will set at 7:16 tomorrow morning.

We are in an eclipse season. These occur at a bit less than 6 months intervals, and last about 35 days. During this period we will have a solar eclipse and a lunar eclipse. Of course the big eclipse of this eclipse season is the April 8th total solar eclipse, which will be visible from the United States and be visible from here as a very deep partial eclipse. We start off this eclipse season with a lunar eclipse, not a really great lunar eclipse, but a lunar eclipse nonetheless. It is a penumbral eclipse where the Moon enters the Earth’s outer shadow where the Sun is only partially blocked to it. What we will see will be not much. It will reach its maximum at 3:13 am Monday morning, when the bottom part of the Moon will be slightly darker than the top.

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

A diagram of the earth's shadow and the Moon at the beginning of the and at the maximum of the penumbral eclipse of next Monday morning
A diagram of the Earth’s shadow and the Moon at the beginning of the and at the maximum of the penumbral eclipse of next Monday morning, March 25th 2024. Created using Cartes du Ciel (Sky Charts). It does give a flavor of what the eclipse kind of looks like. The moon will get a bit dimmer especially the part closest to the umbra, the Earth’s inner shadow. The penumbral shadow is not evenly dark. At the outer edge when the Moon crosses that, nothing will be visible because that bottom edge will go from 100% illuminated by the Sun to maybe 99%, so there’s no visible change at that point. With a penumbral eclipse the only real visible effect is a duskiness on the part of the moon closest to the umbral shadow and it’s usually only within about half an hour in a total or partial eclipse of the moon starting and ending. I’ve found that viewing the moon through sunglasses diminishes the glare of the Moon and allows the penumbral shadow effect to be more easily seen. The image is in alt-azimuth orientation as one would see it from Northern Michigan.
Lunar eclipse diagram
This is a not-to-scale diagram of the motion of the moon through the Earth’s shadow during a lunar eclipse. Assume we are looking down from the north, the motion of the Moon will be counterclockwise. The Moon will enter the shadow from the west or right, so the first “bite” of the shadow will be on the left side of the Moon. The penumbra is a gradually increasing shadow from the outer edge to the umbra, where the Sun is partially blocked by the Earth. In Monday’s eclipse the Moon passes just north of the Earth’s umbral shadow.

Ephemeris: 03/20/2024 – Let’s find out where the naked-eye planets have wandered off to this week

March 20, 2024 Comments off

This is Ephemeris for Wednesday, March 20th. Today the Sun will be up for 12 hours and 11 minutes, setting at 7:56, and it will rise tomorrow at 7:43. The Moon, 3 days past first quarter, will set at 6:38 tomorrow morning.

Let’s find out where the naked-eye planets have wandered off to this week, and see what planets are left. Mercury is visible in the evening sky shortly after sunset appearing very low in the west. It will be visible for the next week or so, moving away from the Sun, but getting dimmer, and starting back toward the Sun after Sunday. Higher up in the sky is bright Jupiter in the west southwest. It will set at 11:45 pm. Jupiter will be visible in the evening for only about another month or so. In the morning Mars, Venus and Saturn may be impossible to spot, in the east-southeast in the bright twilight. Mars will rise at 6:43 am, followed by Venus at 7:13, with Saturn right below it.

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

Jupiter and Mercury as they might appear in the West at around 45 minutes after sunset.
Jupiter and Mercury as they might appear in the West at around 45 minutes after sunset or about 8:40 PM. Created using Stellarium.
The gibbous Moon  as it might be visible this evening in binoculars or a small telescope
The gibbous Moon as it might be visible this evening in binoculars or a small telescope around 9 PM tonight, March 20th, 2024. Selected features are annotated. Created using Stellarium, LibreOffice Draw, and GIMP.
Jupiter and its moons tonight
We are down to one naked eye planet worth looking at in a telescope, and that is Jupiter. This is Jupiter and its moons as they would appear at 9 pm tonight, March 20th 2024. Jupiter and its moons are tilted at an angle as they would appear in the sky due to the angle of the ecliptic to the western horizon. In previous views, where I’ve looked at more than multiple planets at a time, I’ve shown them in relationship to the ecliptic or plane of the Earth’s orbit. Jupiter’s apparent diameter is 34.86 seconds of arc. Created using Stellarium, and LibreOffice Draw for labels.
The naked-eye planets and the Moon at sunset and sunrise on a single night
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right tonight, March 20th 2024. The night ends on the left with sunrise tomorrow morning on the 21st. The symbols and labels for Saturn and Venus in the morning overlay each other. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

Ephemeris: 03/19/2024 – Today is the last day of winter and the first night of spring

March 19, 2024 Comments off

This is Ephemeris for Tuesday, March 19th. Today the Sun will be up for 12 hours and 8 minutes, setting at 7:54, and it will rise tomorrow at 7:44. The Moon, 2 days past first quarter, will set at 6:13 tomorrow morning.

Today, at least in daylight, is the last day of winter. Tonight will be the first night of spring, since spring will arrive at 11:07 pm tonight. This is when the Sun crosses the celestial equator heading northward in the sky, which is actually the Sun moving so it passes overhead and moving north of the equator on the Earth. This gives us in the Northern Hemisphere longer days and warmer temperatures. We call it the vernal or spring equinox. However since some folks are living south of the equator, and are starting autumn at the same time. We sometimes call it the March equinox to recognize that fact. From now until June 20th the Sun will be moving higher in our sky and be staying out longer each day.

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

On the equinoxes, both the vernal and the autumnal equinox, the Sun rises due east and sets due west. Even though the word equinox means equal night, the definition of sunrise and sunset and the fact that we have atmospheric refraction keeps the Sun up more than 12 hours on that day by a few minutes. The altitude of the Sun above the southern horizon at local noon is 90° minus one’s latitude. Created using my LookingUp app.

Ephemeris: 03/18/2024 – Where did the Moon come from?

March 18, 2024 Comments off

This is Ephemeris for Monday, March 18th. Today the Sun will be up for 12 hours and 4 minutes, setting at 7:53, and it will rise tomorrow at 7:46. The Moon, 1 day past first quarter, will set at 5:41 tomorrow morning.

When one gazes upon the moon tonight the thought of where the moon came from comes to mind. Did it form with the Earth? Was it captured by the Earth? The latest thought on the origin of the moon centers around a grazing collision with the Earth of a Mars sized body that has been given the name Theia, the mother of Selene the goddess of the Moon, shortly after the Earth was formed. This is based on the Apollo mission discoveries that the composition of the rocks on the moon are approximately the same as those of the Earth. It has been known for some time that there are two dense masses within the Earth about halfway from the surface to the center. One geologist has put forth the idea that these masses could have been the core of Theia that sank down into the Earth.

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

Collision spawning the Moon
The hypothetical collision of a Mars sized body with the young Earth. Credit: Joe Tucciarone via NASA
New moon formation
A new simulation on how the Moon formed. Our surviving moon would be Moon 2. Moon 1 would crash back to the Earth. Via PBS.
Categories: Ephemeris Program

Ephemeris: 03/15/2024 – The Ides of March

March 15, 2024 Comments off

This is Ephemeris for Ides of March, Friday, March 15th. Today the Sun will be up for 11 hours and 55 minutes, setting at 7:49, and it will rise tomorrow at 7:52. The Moon, 2 days before first quarter, will set at 3:01 tomorrow morning.

Our calendar is derived from the Roman calendar. The Ides is the only named day ion the Roman calendar that we’re familiar with today, the Ides of March. On this day in 44 BCE Roman Emperor Julius Caesar was assassinated. The Ides of a month is the 13th of the month except for March, May, July, and October when it’s the 15th. The Roman calendar has two other named days. The 1st of the month is called Kalend, from which we get our word calendar. The other day is Nones which is the 5th day of the month except for March, May, July, and October when it’s on the 7th. The other days are countdown days to those dates so tomorrow will be the 17th day before the Kalend of April. The countdown is to 1 not 0, if you’re counting.

My source: https://www.slideserve.com/jonah/roman-calendar

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

A statue of Julius Caesar
A statue of Julius Caesar in this uncredited photo. He straightened out the chaotic Roman calendar and established the rule of adding a day every four years to keep the calendar in sync with the seasons. However, the Romans weren’t serious about it until about 8 CE. His calendar is called the Julian Calendar.

This being a leap year, I will spend more time on these programs talking about the calendar. As you may know, we no longer use the Julian calendar for our normal calendar keeping functions. We use the Gregorian Calendar which is a modification of the Julian Calendar that was first made in the year 1582 CE. As we get closer to Easter I will delve into the Gregorian Calendar because it has everything to do with the date of Easter.

Ephemeris: 03/14/2024 – It’s Pi Day!

March 14, 2024 Comments off

This is Ephemeris for Pi Day, Thursday, March 14th. Today the Sun will be up for 11 hours and 52 minutes, setting at 7:48, and it will rise tomorrow at 7:54. The Moon, 3 days before first quarter, will set at 1:47 tomorrow morning.

Yes, it’s Pi day that’s the Greek letter π for 3.14 approximating the ratio of the circle’s circumference to its diameter, which scientific and technical people celebrate by baking a pie P-I-E and carving the Greek letter π on the top.

Tonight around 9 or 9:30 when it gets dark, is a good time to use the Moon to find the Pleiades, the Seven Sisters star cluster. The Pleiades will appear above the crescent Moon this evening, so it’s a good time to locate them if you haven’t already. We only have about another month viewing the Pleiades in the evening. And we have one more passage of the Moon by the Pleiades next month before they disappear from the evening sky.

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

Have a slice of Pi Day pie
Here’s a link to NASA’s Pi Day Challenge: https://www.jpl.nasa.gov/edu/nasapidaychallenge/. This link also has a link for educators for STEM related challenges.
There’s another Pi day that some celebrate. A well-known approximation of pi is the fraction 22/7ths. Europeans and others write dates in day/month order, so July 22nd is also a Pi Day: 22/7.
The moon and the Pleiades as they might be seen this evening in binoculars at 9:00 PM . Jupiter will continue to approach the Pleiades until it sets at 1:44 AM. For locations west of us (Michigan) Jupiter will get even closer. Created using Stellarium.

Ephemeris: 03/13/2024 – Where have the naked-eye planets wandered off to this week?

March 13, 2024 Comments off

This is Ephemeris for Wednesday, March 13th. Today the Sun will be up for 11 hours and 49 minutes, setting at 7:47, and it will rise tomorrow at 7:55. The Moon, 3 days past new, will set at 12:28 tomorrow morning.

Let’s find out where the naked-eye planets have wandered off to this week, and see what planets are left. Mercury is beginning to become visible in the evening sky shortly after sunset appearing very low in the west. It will be visible for the next week or so, moving away from the Sun, but getting dimmer. Higher up in the sky Jupiter and the moon are close together this evening With Jupiter to the left and below the crescent Moon in the west southwest. It will set at 12:08 am. Jupiter will be visible in the evening for only about another month or so. In the morning Mars and Venus may be impossible to spot, in the east-southeast in the bright twilight. Mars will rise at 6:57 am, followed by Venus at 7:21.

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

Looking westward at 8:30 pm or about 45 minutes after sunset tonight, March 13, 2024, Mercury is low in the west. Jupiter and the Moon are much higher in the west-southwest. The Moon has been enlarged to better show its phase. Created using Stellarium.
The moon tonight as it may appear tonight, March 13th 2024, in binoculars or a small telescope with selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
We are down to one naked eye planet worth looking at in a telescope, and that is Jupiter. This is Jupiter and its moons as they would appear at 8:30 pm tonight, March 13th 2024. Jupiter and its moons are tilted at an angle as they would appear in the sky due to the angle of the ecliptic to the western horizon. In previous views, where I’ve looked at more than multiple planets at a time, I’ve shown them in relationship to the ecliptic or plane of the Earth’s orbit. Jupiter’s apparent diameter is 35.31 seconds of arc. Created using Stellarium, and LibreOffice Draw for labels.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on March 13, 2024. The night ends on the left with sunrise on the 14th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

Ephemeris: 03/11/2024 – The Moon and the month

March 11, 2024 Comments off

This is Ephemeris for Monday, March 11th. Today the Sun will be up for 11 hours and 43 minutes, setting at 7:44, and it will rise tomorrow at 7:59. The Moon, 1 day past new, will set at 9:44 this evening.

Tonight’s one-day old moon can be seen in the West shortly after sunset. Astrophysicist Dr. Rebecca Smethurst has a channel on YouTube under the name Dr. Becky. She calls it a toenail moon, because it looks like a toenail clipping. If you look real close, the rest of the Moon may be there. It’s not your eyes playing tricks on you, it’s the Earth shining on the Moon, illuminating the night side of it. For those using lunar calendars this would be day one or two of the lunar month. Since astronomically the Moon was new at 4 am yesterday morning our time. Folks in Europe and Asia may have seen the Moon in the sky last night. The Islamic lunar calendar requires the actual sighting of the new moon to start the month.

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 as it might appear in the western sky about half an hour after sunset tonight
The Moon as it might appear in the western sky about half an hour after sunset tonight, March 11th 2024. At that time the Moon will be 40 hours past its conjunction with the Sun which we call new moon. However, in ancient times, or for those using a lunar calendar, the new moon is the first sighting of the Moon after conjunction with the Sun or after its disappearance from the morning sky. Created using Stellarium.

A note: being a leap year I will have more than my normal amount of posts about the calendar and problems with the calendar.