05/20/2021 – Ephemeris – Our first look at next Wednesday’s lunar eclipse
This is Bob Moler with Ephemeris for Thursday, May 20th. Today the Sun will be up for 15 hours and 1 minute, setting at 9:10, and it will rise tomorrow at 6:08. The Moon, 1 day past first quarter, will set at 3:51 tomorrow morning.
Next Wednesday’s lunar eclipse will be total as seen from half the Earth’s surface, but not the half we’re on. We will catch the start of the eclipse as the Moon is setting, and the Sun is rising. That puts us in a unique position. For 5 minutes between sunrise and moonset we will be able to see both the Sun and the Earth’s shadow falling on the Moon. The Earth’s atmosphere bends the Sun’s red rays into the Earth’s shadow, which is why the Moon usually appears red when totally eclipsed and not completely black. The Sun’s light rays that pass over our heads will continue through our atmosphere to be bent more and will pass into the Earth’s shadow so someone farther west of us can enjoy the red totally eclipsed Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum


The two charts above are contained in a single PDF here-> https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2021May26T.pdf.
UT (Universal Time) to EDT conversion: Subtract 4 hours.
05/19/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, May 19th. Today the Sun will be up for 14 hours and 59 minutes, setting at 9:09, and it will rise tomorrow at 6:09. The Moon, at first quarter today, will set at 3:26 tomorrow morning.
Let’s search for the naked-eye planets for this week. Mars will be joined by two more planets seen in twilight. Both Mercury and Venus are now just above where the Sun set. By 10 pm Mercury should be able to be spotted low in the west-northwest. Venus might be spotted lower and somewhat earlier, it’s a lot brighter than Mercury. Venus will be setting at 10:21 pm with Mercury following at 11:04. Mars can be found in the west at 10:30 tonight, in the constellation of Gemini the twins. Tonight it’s in the middle of the constellation. Mars will set at 12:42 am. Jupiter and Saturn, are in the morning sky. Saturn will rise at 2:03 am, with brighter Jupiter rising at 2:43 am. By 5 am they will be in the southeast in the morning twilight.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum




05/18/2021 – Ephemeris – Eclipses visible in Northern Michigan this year
This is Ephemeris for Tuesday, May 18th. Today the Sun will be up for 14 hours and 56 minutes, setting at 9:08, and it will rise tomorrow at 6:10. The Moon, 1 day before first quarter, will set at 2:57 tomorrow morning.
This year we will see in part or in full three eclipses from our Northern Michigan location. The first will be the start of a total lunar eclipse next week Wednesday, May 26th. It will start just before sunrise, which for a full moon is around moonset. Our next eclipse will be a solar eclipse that starts, for us, before sunrise on June 10th. In fact, most of the eclipse will occur before sunrise for us in Northern Michigan. The farther north and east of us the more of the eclipse you’ll see. I’ll have more information on the lunar in the next week of programs. And the solar eclipse as we approach that date. We have a final lunar eclipse this year. That will occur in the wee morning hours of November 19th, a partial, but almost total eclipse.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The four eclipses that occur in 2021
We in Northern Michigan we’ll see part of the first two and all of the third.
May 26, 2021 Total Lunar Eclipse

June 10, 2021 Annular Solar Eclipse

November 19, 2021 Partial Lunar Eclipse

December 4, 2021 Total Solar Eclipse
05/17/2021 – Ephemeris – The Moon tonight
This is Ephemeris for Monday, May 17th. Today the Sun will be up for 14 hours and 54 minutes, setting at 9:06, and it will rise tomorrow at 6:11. The Moon, 2 days before first quarter, will set at 2:25 tomorrow morning.
The Moon tonight reveals a bit more territory than it did last night, and will every night until full moon. The Moon’s solar day equals a lunar month of about 29 and a half of our days. As seen in binoculars, below and left of The distinctly oval Sea of Crises, or Mare Crisium, is the Sea of Fertility, or Mare Fecunditatis. To the left of the Sea of Crises, the Sea of Tranquility (Tranquilitatis) where the Apollo 11 crew landed. Above that half of Sea of Serenity has come into daylight. Tonight the Beehive star cluster will be visible below and left of the Moon. It should be easily visible in binoculars and has a vaguely triangular shape. It was known to the ancients as Praesepe, the manger, who saw it as a glowing spot on moonless nights.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum

05/14/2021 – Ephemeris – Astronomy Day Star Party this Saturday
This is Bob Moler with Ephemeris for Friday, May 14th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:03, and it will rise tomorrow at 6:14. The Moon, 3 days past new, will set at 12:07 tomorrow morning.
Tomorrow is International Astronomy Day, to celebrate it the Sleeping Bear Dunes National Lakeshore and Grand Traverse Astronomical Society will hold a special virtual star party via the Zoom Internet app. If it’s clear, Northwestern Michigan College’s professor Jerry Dobek will be transmitting live images of celestial objects that will look pretty much like what one sees through the eyepiece of a telescope. Dr. Dobek will be using the Joseph H. Rogers 0.4 meter main telescope and commenting will be members of the Grand Traverse Astronomical Society. Featured objects will be the 4-day-old crescent Moon, the tiny and elusive planet Mercury, star clusters and galaxies. The event starts at 9 pm though best viewing won’t begin until after about 9:30. Go to www.gtastro.org for instructions and a link.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
While attending the virtual star party you can capture the screen imaged with Alt/Print Screen keys. Paste the image into a paint or other program. I use GIMP (Gnu Image Manipulation Program), which fits my budget… It’s free. You can save the image of play with it. What I do with it is to darken the background. It should be black.

I paste this image into GIMP. I use the Levels control under the Color tab.
05/13/2021 – Ephemeris – The Moon and Mercury will appear near one another tonight
This is Ephemeris for Thursday, May 13th. Today the Sun will be up for 14 hours and 45 minutes, setting at 9:02, and it will rise tomorrow at 6:15. The Moon, 2 days past new, will set at 11:08 this evening.
Tonight starting around 9:30, or half an hour after sunset is a good time to spot the thin crescent two day old Moon and the planet Mercury. The tiny and elusive Mercury will be about 7 moon widths to right of the Moon. With the Moon near Mercury, it should be easier to find instead of trying to locate it in the great expanse of featureless twilit sky. Mercury has a weird rotational period. In my youth astronomers thought that Mercury rotated so that one face would perpetually face the Sun, So it would rotate in the same time it orbits the Sun of 88 days. That’s what happens when the Moon orbits the Earth. However, Mercury rotates in exactly 2/3rds of its orbital time, making its solar day two of its years long or 176 Earth days.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum


05/12/2021 – Ephemeris – Searching for the naked-eye planets for this week
This is Ephemeris for Wednesday, May 12th. Today the Sun will be up for 14 hours and 43 minutes, setting at 9:01, and it will rise tomorrow at 6:16. The Moon, 1 day past new, will set at 10:06 this evening.
Let’s search for the naked-eye planets for this week. Mars will be joined by two more planets seen in twilight. Both Mercury and Venus are now just above where the Sun set. By 9:30 pm Mercury should be able to be spotted low in the west-northwest. Venus might be spotted lower and somewhat earlier. Venus will be setting at 10:02 pm with Mercury following at 11 pm. Mars can be found in the west at 10 pm tonight, in the constellation of Gemini the twins. Tonight it’s in the middle of the constellation. Mars will set at 1:02 am. Jupiter and Saturn, are in the morning sky. Saturn will rise at 2:30 am, with brighter Jupiter rising at 3:13 am. By 5:30 am they will be low in the southeast in the morning twilight.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum




05/11/2021 – Ephemeris – The Big Dipper as seen by many peoples
This is Ephemeris for Tuesday, May 11th. Today the Sun will be up for 14 hours and 41 minutes, setting at 9 pm, and it will rise tomorrow at 6:17 am. The Moon is new today, and won’t be visible.
The Big Dipper is overhead, actually north of overhead this evening when it gets dark for us in Michigan, it’s seven stars shining brightly. The Big Dipper is not an actual constellation, recognized internationally. It’s part, the hind part, of Ursa Major, the great bear. The Big Dipper is an asterism or informal constellation. It is a distinctly North American constellation. For fugitive slaves, fleeing the southern states in the days before the Civil War, the Drinking Gourd, as they called it, showed the direction north to freedom. In England the dipper stars become the Plough (plow), or Charles’ Wain (Charlemagne’s Wagon). In France, known for culinary delights it was the saucepan, or the cleaver. Many cultures saw what was familiar to them in these seven bright stars.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
05/10/2021 – Ephemeris – The story of the constellations Boötes and Ursa Major
This is Bob Moler with Ephemeris for Monday, May 10th. Today the Sun will be up for 14 hours and 38 minutes, setting at 8:58, and it will rise tomorrow at 6:18. The Moon, 1 day before new, will rise at 6:25 tomorrow morning.
Seen in the east at 10 p.m. tonight is the kite shaped constellation of Boötes the herdsman. The bright star Arcturus is at the bottom of the kite to the right. It is pointed to by the arc of the handle of the Big Dipper, higher in the east. Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young lady who had the misfortune of being loved by Zeus the chief of the Greek gods. Zeus’ wife Hera, found out about it, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of the events surrounding his mother’s disappearance was about to kill the bear when Zeus intervened and placed them both in the sky to save her, as Arcas still pursues her across the sky nightly.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
05/06/2021 – Ephemeris – Corvus, Crater, Hydra and Apollo
This is Ephemeris for Thursday, May 6th. Today the Sun will be up for 14 hours and 28 minutes, setting at 8:54, and it will rise tomorrow at 6:24. The Moon, 3 days past last quarter, will rise at 5:04 tomorrow morning.
The small constellation of Corvus the crow is located low in the south at 10:30 this evening. It’s made of 5 dim stars, but the pattern is a distinctive but distorted box with two stars at the upper left marking that corner. To the right is a fainter constellation of a thick stemmed goblet called Crater. Both appear above the long constellation of Hydra the water snake who is slithering just above the southern horizon. In Greek mythology Corvus, then white, was the god Apollo’s pet. Apollo once bid Corvus to take a cup and fetch him some water. Corvus however dallied and waited for a green fig to ripen. He grabbed a snake and returned with a story as to how the snake had delayed him. The angry Apollo turned the crow and all crows to this day black.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.










