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11/07/2022 – Ephemeris – There will be a total eclipse of the Moon in the hours before sunrise tomorrow morning

November 7, 2022 Comments off

This is Bob Moler with Ephemeris for Monday, November 7th. Today the Sun will be up for 9 hours and 54 minutes, setting at 5:23, and it will rise tomorrow at 7:30. The Moon, 1 day before full, will set at 7:40 tomorrow morning.

There will be a total eclipse of the Moon tomorrow morning. We in Michigan are near the eastern edge of the part of the Earth that can see the eclipse. The partial phase will begin at 4:09 am. More and more of the Moon will enter the Earth’s inner shadow, until 5:16 am, when the Moon will be completely eclipsed. We expect the Moon to have a reddish hue from sunlight leaking and bent through Earth’s atmosphere into the shadow. This total phase will last until 6:41 am, when the Moon will begin to emerge into sunlight to start the ending partial phase of the eclipse. By this time, the Moon will be getting low in the west. The Moon will set around 7:40 am, just before the end of the eclipse and a few minutes after sunrise.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 5 hours). They may be different for your location.

Addendum

Credit: NASA/GSFC, Fred Espenak. Click on the image for the full size PDF file from the NASA eclipse site.

The contact times again for Eastern Standard Time

Contact                     Time EST
U1 Partial eclipse starts...4:09 am
U2 Totality starts..........5:16 am
   Mid-eclipse..............6:00 am
U3 Totality ends............6:41 am
U4 Partial eclipse ends.....7:49 am

P1 and P4 are not noticeable, so are not listed. The penumbral shadow will be noticeable, generally for a half hour or so before U1 and again for a half hour or so after U4, if you are located far enough west of here to see the complete eclipse.

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.

The Moon’s appearance in totality

The Moon will normally appear to have a dull reddish hue during totality, though the edge of the umbra will normally appear gray. When there is a spectacular volcanic eruption, the volcanic dust in the atmosphere can produce an especially dark eclipse. The normal red color is due to all the sunrises and sunsets occurring on the Earth during the eclipse. The atmosphere scatters out the blue component of the sunlight, giving us red sunrises and sunsets. Also, the atmosphere refracts or bends the sunlight into the Earth’s inner shadow, the umbra, at the Moon’s distance, so the totally eclipsed Moon isn’t completely dark.

10/25/2022 – Ephemeris – This eclipse season starts with a partial solar eclipse, but not for us

October 25, 2022 Comments off

“But not for us” means not for Michigan in the United States. This is a script, as always, for a local radio program. Which also mentions the midterm election day, two weeks from now, which coincides with the total lunar eclipse that morning. I’ll have an Ephemeris Extra post before the lunar eclipse, which looks into the next few lunar and solar eclipses visible in Michigan and the United States.

This is Ephemeris for Tuesday, October 25th. Today the Sun will be up for 10 hours and 30 minutes, setting at 6:41, and it will rise tomorrow at 8:12. The Moon is new today, and won’t be visible.

The Moon will be visible in a negative way for some folks at this time. There is a partial solar eclipse in progress now for parts of Europe, Asia and Africa. So that thing blocking the northern part of the Sun for them will be the Moon. Being a partial eclipse means that an eclipse season has started, and we should have a lunar eclipse in about two weeks, when the Moon is full. There sure is, and it’s visible from here. In exactly two weeks, there will be. In the early morning hours of November 8th, Election Day, a total eclipse of the Moon. And if you’re standing outside the polling place waiting for the polls to open at 7 am, and it’s clear, and you have a view to the west, the partially eclipsed Moon will still be visible. That will be the ending partial phase of the eclipse.

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

October 25 2022 solar eclipse map

Map for the area on the Earth where the partial solar eclipse of October 25, 2022, will be visible. Credit: NASA/GSFC, Fred Espenak.

07/28/2022 – Ephemeris – Why don’t we have solar eclipses every new moon?

July 28, 2022 Comments off

This is Bob Moler with Ephemeris for Thursday, July 28th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon is new today, and won’t be visible.

The actual time when the moon is New will be 1:55 pm. The Moon will not eclipse the Sun this time. Why? Because the Moon is nearly 5 degrees, or 10 moon-diameters, north of the Sun. If the Moon orbited the Earth nearly in the same plane that the Earth orbited the Sun, we could have solar eclipses for somewhere on the Earth every new moon. As it is, the Moon orbits the Earth with about a 5-degree tilt to the Earth’s orbit of the Sun. So we get eclipse opportunities of eclipses about one in six new moons for solar eclipse and about the same for full moons and lunar eclipses. Of course, one has to be at the proper location to see them. If the Moon orbited the Earth over the Earth’s equator, like many other moons of other planets, eclipses would be much more rare and only occur around the equinoxes.

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 Sun and Moon at New Moon 7/28/2022

The Sun and Moon at New Moon at 1:55 pm today, seen as if the Earth had no atmosphere and one could see the Sun and stars at the same time. The orange line is the path of the Sun in the sky, called the ecliptic. The red line is the orbit of the Moon. Created using Stellarium.

Sun and Moon's orbits on the celestial sphere

Earth centered (geocentric) diagram of the heavens called the celestial sphere, showing the apparent orbits of the Sun and Moon. The Moon’s orbit has about a 5-degree tilt (exaggerated here) to the Sun’s apparent orbit, which we call the ecliptic. Solar eclipses occur when the new moon and Sun are near a node. Lunar eclipses occur when the full moon and Sun are near opposite nodes. My diagram.

The orbit of the Moon precesses, so the line of the nodes regresses, that is slowly rotating clockwise, backwards to the motion of the Sun and Moon (and all the rest of the planets), one rotation in 18.6 years.

05/16/2022 – Ephemeris – More eclipses in our future

May 16, 2022 Comments off

This is Ephemeris for Monday, May 16th. Today the Sun will be up for 14 hours and 52 minutes, setting at 9:05, and it will rise tomorrow at 6:12. The Moon, at full today, will rise at 10:13 this evening.

Last night’s eclipse was the only eclipse that was visible in our area this year. However, in the next two years we will have a chance, weather permitting, to see two partial solar eclipses, the second of which will be even better than the partial solar eclipse seen here in August 2017. On October 14, 2023, there will be an annular eclipse. An annular eclipse is where the Moon is too far away to completely cover the face of the Sun. It leaves a ring of bright sun around the Moon. The technical term for a ring like that is annulus. The path of annularity will run from Oregon to Texas. For the Grand Traverse Area of Michigan, the Moon will cover less than half the face of the Sun. On April 8, 2024, the total eclipse path will run from Texas to Maine and just nip the Southeast corner of Michigan covering, for us in the Grand Traverse Area, about 85 percent of the Sun.

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

Path across US of Ocober 14 2023 annular solar eclipse

The areas where the October 14, 2023 solar eclipse can be seen are bounded by the outer green lines. The path where the annular part of the eclipse is visible is denoted by the triple green lines. Plotted on Google Earth using a file created by Occult4 software from the International Occultation Timing Association.

Path across the US of the April 8 2024 total solar eclipse

The areas across the U.S. where the April 8, 2024 solar eclipse can be seen are bounded by the outer green lines. The path where the total part of the eclipse is visible is denoted by the triple green lines. Plotted on Google Earth using a file created by Occult4 software from the International Occultation Timing Association.

05/13/2022 – Ephemeris – Remember, there is going to be an eclipse of the Moon late Sunday night!

May 13, 2022 Comments off

This is Bob Moler with Ephemeris for Friday, 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, 3 days before full, will set at 5:28 tomorrow morning.

There is going to be an eclipse of the Moon running from late Sunday night into the early Monday morning hours. That’s the night of May 15/16. By 10:30 pm, there will appear a noticeable “bite” out of the lower left edge of the Moon as it enters the Earth’s inner shadow, called the umbra. The shadow will creep across the Moon for the next hour. And by 11:30 the Moon is completely immersed in the Earth’s inner shadow. By now, one will notice that the shadow is not completely black. The Moon usually has a dim reddish hue caused by all the simultaneous sunrises and sunsets around the Earth. This is the total phase of the eclipse, which will last until almost 1 am. The Moon will slowly exit the inner shadow by 2 am.

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

05-16-22 Lunar eclipse diagram2

The eclipse occurs on the 16th for Universal Time, because the eclipse events take place after 8 pm EDT on the 15th. The Moon travels through the Earth’s shadow from right to left. What are seen are points of contact with the shadow and mid-eclipse. From Five Millennium Canon of Lunar Eclipses (Espenak & Meeus) NASA, with additions.

Contact times are labeled P1, U1, U2, U3, U4, and P4. P2 and P3 are omitted because they are synonymous with U1 and U4, respectively. Times are EDT unless noted:

  • P1 – 9:32:07 pm (1:32:07 UT) Enter the penumbra (unseen). By about 10 pm, the duskiness on the left edge of the moon will start to be noticeable. Wearing sunglasses to dim the bright Moon will help show the effect.
  • U1 – 10:27:53 pm (2:27:53 UT) Enter the umbra (partial eclipse begins).
  • U2 – 11:29:03 pm (3:29:03 UT) Totality begins.
  • Mid-eclipse 12:11:28.8 am (4:11:28.8 UT)
  • U3 – 12:53:56 am (4:53:56 UT) Totality ends, the egress partial phase begins.
  • U4 – 1:55:07 am (5:55:07 UT) Partial phase ends. The Moon’s upper right edge should appear dusky for the next half hour or so.
  • P4 – 2:50:48 am (6:50:48 UT) Penumbral phase ends (unseen).
Surveyor3 solar eclipse

Solar eclipse by the Earth as photographed by Surveyor 3, which had landed on the Moon, April 24, 1967. The Earth was seeing a lunar eclipse at the time. Light seeps into the Earth’s shadow at the Moon’s distance due to atmospheric refraction. The amount of light depends on the atmospheric conditions at the time. Great volcanic eruptions can cause a very dark, nearly invisible, eclipsed Moon. Credit: NASA.

Update 7:30 pm, May 15th

In note for P1 time: Expected actual visibility of penumbral shadow is changed to 10 pm (2 hr UT).

05/21/2021 – Ephemeris – For everything there is a season… even eclipses

May 21, 2021 Comments off

This is Ephemeris for Friday, May 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:11, and it will rise tomorrow at 6:07. The Moon, 2 days past first quarter, will set at 4:14 tomorrow morning.

There are seasons for everything: baseball season, football season, spring, summer, what have you. There are also eclipse seasons. The Moon’s orbit is tilted by about 5 degrees to the ecliptic, the path of the Sun in the sky. The points where they cross are called nodes, 180 degrees apart. When the Sun is near one of those nodes we are in an eclipse season, where a solar eclipse can occur at new moon, and a lunar eclipse can occur at full moon. We are guaranteed one of each per eclipse season, and on rare occasions a third eclipse. Of course one has to be at the right place to see an eclipse. This eclipse season we will be at a marginal place to see both eclipses. Both are at sunrise, so we’ll see just a part of each of them.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Apparent paths of the Sun and Moon against the sky
A diagram of the paths of the Moon and Sun projected on the sky (celestial sphere). N1 and N2 are the nodes (crossing points). Nodes are ascending or descending depending on the northerly or southerly component of the Moon’s motion in crossing them. The Sun and Moon move in an easterly direction, but the Moon’s orbit precesses so that the line of nodes move in a westerly direction once around in 18.6 years. That’s why eclipse season intervals are 173.3 days and move backward in the calendar one year to the next. Eclipse seasons occur when the Sun is less than about 17.5 degrees from a node. Credit Earthsky.org.

For a more extensive treatment of this subject check out: https://earthsky.org/astronomy-essentials/definition-what-is-an-eclipse-season

05/18/2021 – Ephemeris – Eclipses visible in Northern Michigan this year

May 18, 2021 Comments off

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
The visibility map for the May 26th total lunar eclipse. Note Michigan’s mitten lies between the U1 and U2, which means that the Moon will set after the partial eclipse starts, but before totality. Credit: NASA/GSFC/Fred Espenak

June 10, 2021 Annular Solar Eclipse

The visibility map for the June 10, 2021 annular solar eclipse. In an annular eclipse the Moon is too far away and appears too small to cover the face of the Sun. So, at maximum a ring of bright Sun surrounds the Moon. It’s sometimes called a ring of fire. For locations within the big floppy figure 8 the eclipse either ends near sunrise or starts near sunset. The double red line with the ellipses in it is the path of where the ring is visible. Locations within the blue grid will see a partial eclipse. Credit: NASA/GSFC/Fred Espenak.
November 19, 2021 Partial Lunar Eclipse
The visibility map for the November 19, 2021 partial eclipse. The eclipse is visible in its entirety in the morning of the 19th. This eclipse is almost total. Credit: NASA/GSFC/Fred Espenak.
December 4, 2021 Total Solar Eclipse
Visibility map for the December 4, 2021 total solar eclipse. Totality is onlt visible from the Southern Ocean and Antarctica, Credit: NASA/GSFC/Fred Espenak.

12/31/2020 – Ephemeris – Looking ahead at the eclipses of 2021

December 31, 2020 Comments off

This is Ephemeris for New Year’s Eve, Thursday, December 31st. The Sun will rise at 8:20. It’ll be up for 8 hours and 52 minutes, setting at 5:12. The Moon, 2 days past full, will rise at 6:43 this evening.

I’ve had enough of 2020, and I hope in 2021 that we’ll break the grip of this pandemic. Looking up next year we will get glimpses of three of the four eclipses that will occur in 2021. We will get a chance to see the beginning of an eclipse of the Moon at sunrise as it sets on May 26th. Fifteen days later, on June 10th we will be able to see the Sun rise while being partially eclipsed by the Moon. People in western Ontario, up through northern Canada, then across the North Pole and into Siberia will get to see an annular or ring of fire eclipse of the Sun. On November 19th, clouds willing, we will get to see an almost total eclipse of the Moon that morning with over 97 percent of the Moon covered by the Earth’s inner shadow.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Sun rises in eclipse - June 10, 2021

What might it look like when the Sun will rise in eclipse for the Grand Traverse region of Michigan at about 6:10 am June 10, 2021. Note that you, or actually your location, is involved in what you can see of a solar eclipse. Created using Stellarium.

Lunar Eclipse maximum 4:04 am 11/19/21

What the lunar eclipse maximum might look like at 4:04 am (9:04 UT), November 19, 2021. Created using Stellarium.

There is a fourth eclipse in 2021, a total solar eclipse that is mainly visible in the Southern Ocean and Antarctica on December 4, 2021.

 

 

11/30/2020 – Ephemeris – We’ve entered an eclipse season

November 30, 2020 Comments off

This is Bob Moler with Ephemeris for Monday, November 30th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:03, and it will rise tomorrow at 8:00. The Moon, at full today, will rise at 5:22 this evening.

This morning we had a slight eclipse of the Moon, where the Moon entered only the southern part of the Earth’s penumbral or partial shadow. On December 14th, at the next new moon there will be a total eclipse of the Sun that will be visible from South America. We are now in an eclipse season which lasts about 35 days. In that time two or rarely three eclipses can be fit in. The next eclipse season is 5 months and 18 days away in late May and early June 2021. Then there will be, for Michigan, the start of a lunar eclipse visible just before sunrise on May 26th and the end of a solar eclipse visible at sunrise on June 10th. Those two eclipses will just be teasing us. Our next nearby total solar eclipse is less than three and a half years away on April 8, 2024.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Explaining eclipse seasons, NASA/JPL

A diagram showing eclipse seasons. Though only solar eclipses are shown, it also includes lunar eclipses. Three months later (actually only a month later) the shadows of each are either too far north or south to fall on the other. Click on the image to enlarge. Credit: NASA/JPL

11/23/2020 – Ephemeris – Our Moon is different

November 23, 2020 Comments off

This is Bob Moler with Ephemeris for Monday, November 23rd. Today the Sun will be up for 9 hours and 16 minutes, setting at 5:07, and it will rise tomorrow at 7:52. The Moon, 2 days past first quarter, will set at 1:55 tomorrow morning.

The Earth’s Moon is different from most other moons. First it is very big when compared to the Earth. The Moon is a bit more than quarter the Earth’s diameter. Only Pluto’s moon Charon is larger compares to its primary, being half the size of Pluto. Most big moons orbit over their planet’s equator. Our Moon orbits the Earth close to the plane of Earth’s orbit of the Sun. That’s why the Moon is seen passing the planets each month. The Moon is too big to have been captured by the Earth in a chance flyby. The moon rocks brought back during Apollo showed that the Moon was made of the same crustal material as the Earth, so the impact theory was put forth that the Moon was the result of a collision of the Earth and a Mars sized body soon after they were formed.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Moon's orbit vs the ecliptic

The Moon’s orbit (red) vs the ecliptic or plane of the Earth’s orbit (orange). The Moon’s orbit is tilted to the Earth’s orbit by 5 degrees. This is for 4:30 pm or a little more than a half hour before sunset. The black sky is due to removing atmospheric scattering in the program. Click on the image to enlarge. Created using Stellarium.

In the image note that the Moon’s orbit crosses the ecliptic just east of the Sun’s position. That crossing point is called the Moon’s descending node, since the Moon’s eastward motion will take it from north of the ecliptic to south of it. When the Sun is close to a node eclipses can occur. The ascending node is at the opposite side of the ecliptic so both solar and lunar eclipses occur in an eclipse season that lasts about a month.

An indeed there will be a penumbral eclipse of the Moon on the 30th, and a total solar eclipse for Chile and Argentina December 14th. The nodes don’t stay in one place, but they move westward, making one rotation around the ecliptic in 18.61 years. Since the nodes are moving westward it is called the regression of the nodes. So eclipse seasons occur about every 5 2/3 months, moving backwards in the calendar.