Archive for the ‘Lunar Eclipse’ Category

08/08/2017 – Ephemeris – Eclipse seasons

August 7, 2017 1 comment

Ephemeris for Monday, August 7th. The Sun rises at 6:36. It’ll be up for 14 hours and 23 minutes, setting at 8:59. The Moon, at full today, will rise at 9:00 this evening.

At two weeks before the great solar eclipse, the world is experiencing another eclipse, this one is a partial lunar eclipse where the Moon will just clip the northern part of the Earth’s shadow this afternoon our time. It will be mainly visible from Asia. Eclipses occur in seasons of about a month long that occur at a bit less than six month intervals, so eclipses will occur a little earlier next year to the this. That’s because the crossing points of the Moon’s and the Earth’s orbital planes regress slowly westward. In an eclipse season two eclipses will occur: a solar and a lunar eclipse. On rare occasion when a lunar eclipse occurs in the center of a season a partial solar eclipse can occur two weeks before and again after the lunar eclipse, but they will affect the opposite polar regions of the Earth.

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


Table of this and next three eclipse seasons

Date Eclipse Type Notes
08/07/2017 Lunar Eclipse – partial Moon clips northern part of Earth’s umbra
08/21/2017 Solar Eclipse – total Path of totality crosses US
01/31/2018 Lunar Eclipse – total Moon crosses just south of center of umbra
02/15/2018 Solar Eclipse – partial  Visible mostly from Antarctica
07/13/2018 Solar Eclipse – partial Seen from southern Australia
07/27/2018 Lunar Eclipse – total Moon crosses center of umbra
08/11/2018 Solar Eclipse – partial Seen from northern Europe, Asia
01/06/2019 Solar Eclipse – partial Seen mostly from northern Pacific Ocean
01/21/2019 Lunar Eclipse – total Moon crosses just north of center of umbra

07/10/2017 – Ephemeris – There’s a penumbral eclipse of the Moon tonight

February 10, 2017 Comments off

Ephemeris for Friday, February 10th.  The Sun will rise at 7:49.  It’ll be up for 10 hours and 15 minutes, setting at 6:04.  The Moon, at full today, will rise at 5:58 this evening.

This evening there will be a penumbral eclipse of the moon, which will reach its peak at 7:45 p.m.  The moon, on its left side will be slightly darkened as the Moon passes through the Earth’s partial outer shadow where the Sun is only partially blocked by the Earth.  Only the left side of he Moon will show the effect, which is best seen wearing sunglasses to reduce the Moon’s glare.  The Northwestern Michigan College’s Rogers Observatory will be open to view the event from 6:45 to 8:45 p.m. but only if it’s clear.  This event does not require a telescope to appreciate, but it might be nice to view it with others.  The observatory is located south of Traverse City on Birmley Road between Keystone and Garfield roads.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Lunar Eclipse Geometry

How lunar eclipses occur. For this eclipse the Moon will miss the umbra but will penetrate the deep into the penumbra.  Credit NASA/Fred Espenak.

Eclipse Diagram

Diagram of the penumbral lunar eclipse on the evening of February 10, 2016 for the Eastern time zone. Diagram adapted from Fred Espenak, NASA GSFC.

February 10, 2017 Penumbral Eclipse of the Moon

This is the maximum of the February 10th penumbral lunar eclipse. The Moon will appear to move diagonally down to the left. It is shown at maximum eclipse at 7:45 p.m. (0:45 UT February 11). The diagram is oriented for viewing from northern Michigan. Created using Cartes du Ciel.

NASA’s pdf page on this eclipse:

02/09/2017 – Ephemeris – Tomorrow’s penumbral eclipse of the Moon

February 9, 2017 Comments off

Ephemeris for Thursday, February 9th.  The Sun will rise at 7:50.  It’ll be up for 10 hours and 12 minutes, setting at 6:03.  The Moon, 1 day before full, will set at 7:28 tomorrow morning.

Tomorrow evening, clouds willing, we see an odd partial eclipse of the Moon called a penumbral lunar eclipse.  What is a penumbra?  It’s the fuzzy outer part of a shadow that’s cast when the light source isn’t a pin point.  Look at your shadow in the sunlight, especially that of your head.  The outline isn’t sharp.  That outer fuzziness of the shadow is your penumbra where the Sun isn’t completely blocked., while the dark inner shadow is the umbra, where the Sun is completely blocked by your head.  Tomorrow evening  the eclipse will actually start before the Moon rises.  The Moon should appear pretty much normal until it passes deep into the penumbra of the Earth’s shadow.  Deepest penetration will occur at 7:45 pm. Where the upper left part of the Moon will appear dimmer than the rest of it.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


Eclipse Diagram

Diagram of the penumbral lunar eclipse on the evening of February 10, 2016 for the Eastern time zone. Diagram adapted from Fred Espenak, NASA GSFC.

P1 is the first contact with the shadow and P4 the last.  Nothing will be noticed at these times.  Only when closest to the greatest eclipse will the part of the moon nearest the inner shadow will show darkening.

Eclipse map

Only from the lighter parts of the map will the eclipse be visible. Diagram from Fred Espenak, NASA GSFC.

01/31/2017 – Ephemeris – Looking ahead at February 2017

January 31, 2017 1 comment

Ephemeris for Tuesday, January 31st.  The Sun will rise at 8:02.  It’ll be up for 9 hours and 48 minutes, setting at 5:50.  The Moon, 3 days before first quarter, will set at 10:06 this evening.

February is the shortest month, even so the daylight hours throughout the month will be getting longer.  Daylight hours will increase from 9 hours and 50 minutes tomorrow to 11 hours and 7 minutes on the 28th.  The sunrise time will decrease from 8:01 tomorrow to 7:21 at months end.  The sunset times will increase from 5:51 tomorrow to 6:29 on the 28th.  Along with that the altitude of the sun at noon will increase from 28.4 degrees today to  38.6 degrees at month’s end.  It will be a degree lower for folks in the Straits area because they are a degree of latitude farther north.  Local noon, by the way for Interlochen and Traverse City is about 12:55 p.m. On the evening of the 10th the Moon will enter the Earth’s outer shadow with an penumbral lunar eclipse.  I’ll have more information on that then.  Moon will be near the planets Mars and Venus in the southwestern sky early tonight.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


February Star Charts

February evening skies

Star Chart for February 2017. Created using my LookingUp program. Click on image to enlarge.

The sky on February mornings

Star Chart for February 2017 mornings. Created using my LookingUp program. Click on image to enlarge.

 Since the night time hours are long I’ve decided to add a morning star chart .

The planets and stars are plotted for the 15th at 9 p.m. EST, and again at 6 a.m.  Those are chart times.  Note, Traverse City is located approximately 45 minutes behind our time meridian.  (An hour 45 minutes behind our daylight saving time meridian. during EDT and 45 minutes behind our daylight standard time meridian. during EST).  To duplicate the star positions on a planisphere you may have to set it to 1:45 or 0:45  earlier than the current time if you were near your time meridian.

Add a half hour to the chart time every week before the 15th and subtract a half hour for every week after the 15th.

For a list of constellation names to go with the abbreviations click here.

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star
  • Follow the arc of the handle of the Big Dipper to the star Arcturus, and
  • Straighten to a spike to Spica
  • The Summer Triangle is shown in red

Evening nautical twilight ends at 6:56 p.m. EST on the 1st, increasing to 7:31 p.m. EST on the 28th.
Evening astronomical twilight ends at 7:30 p.m. EST on the 1st, increasing to 8:05 p.m. EST on the 28th.
Morning astronomical twilight starts at 6:22 a.m. EST on the 1st, and increasing to 5:45 a.m. EST on the 28th.
Morning nautical twilight starts at 6:56 a.m. EST on the 1st, and Increasing to 6:19 a.m. EST on the 28th.

NASA Calendar of Planetary Events

Credit:  Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)

To generate your own calendar go to

Times are Eastern Time and follow the time change dates.

Date        Time    Event
Feb 01  We          Venus: 45.5° E
    02  Th  5:11 am Venus-Mars: 5.4° N
    03  Fr 11:19 pm First Quarter
    05  Su  4:14 pm Moon-Aldebaran: 0.2° S
    06  Mo  8:59 am Moon Perigee: 368800 km
    07  Tu  1:34 pm Moon North Dec.: 18.9° N
    10  Fr  7:33 pm Full Moon
    10  Fr  7:45 pm Penumbral Lunar Eclipse
    11  Sa  9:04 am Moon-Regulus: 0.8° N
    11  Sa  2:49 pm Moon Ascending Node
    15  We  9:55 am Moon-Jupiter: 2.9° S
    18  Sa  2:33 pm Last Quarter
    18  Sa  4:14 pm Moon Apogee: 404400 km
    20  Mo  6:44 pm Moon-Saturn: 3.9° S
    21  Tu  3:50 pm Moon South Dec.: 18.8° S
    26  Su  1:28 pm Moon Descending Node
    26  Su  9:54 am Annular Solar Eclipse - South Atlantic
    26  Su  9:58 am New Moon
Mar 01  We          Venus: 32.5° E

February 2017 Calendar

LU             Ephemeris of Sky Events for Interlochen/TC
February, 2017    Local time zone: EST
|Wed  1| 08:01a  05:51p  09:50 | 06:57p  06:55a |      Set  11:15p   26%|
|Thu  2| 08:00a  05:53p  09:52 | 06:59p  06:54a |      Set  12:25a   37%|
|Fri  3| 07:59a  05:54p  09:55 | 07:00p  06:53a |F Qtr Set  01:35a   48%|
|Sat  4| 07:57a  05:56p  09:58 | 07:01p  06:52a |      Set  02:45a   59%|
|Sun  5| 07:56a  05:57p  10:00 | 07:03p  06:51a |      Set  03:53a   70%|
|Mon  6| 07:55a  05:58p  10:03 | 07:04p  06:50a |      Set  04:56a   80%|
|Tue  7| 07:54a  06:00p  10:06 | 07:05p  06:48a |      Set  05:54a   89%|
|Wed  8| 07:52a  06:01p  10:09 | 07:06p  06:47a |      Set  06:45a   95%|
|Thu  9| 07:51a  06:03p  10:11 | 07:08p  06:46a |      Set  07:28a   99%|
|Fri 10| 07:50a  06:04p  10:14 | 07:09p  06:45a |Full  Rise 05:59p  100%|
|Sat 11| 07:48a  06:06p  10:17 | 07:10p  06:43a |      Rise 07:06p   99%|
|Sun 12| 07:47a  06:07p  10:20 | 07:12p  06:42a |      Rise 08:12p   96%|
|Mon 13| 07:45a  06:08p  10:23 | 07:13p  06:41a |      Rise 09:16p   90%|
|Tue 14| 07:44a  06:10p  10:26 | 07:14p  06:39a |      Rise 10:18p   84%|
|Wed 15| 07:42a  06:11p  10:28 | 07:15p  06:38a |      Rise 11:18p   76%|
|Thu 16| 07:41a  06:13p  10:31 | 07:17p  06:37a |      Rise 12:18a   67%|
|Fri 17| 07:39a  06:14p  10:34 | 07:18p  06:35a |      Rise 01:16a   58%|
|Sat 18| 07:38a  06:15p  10:37 | 07:19p  06:34a |L Qtr Rise 02:12a   48%|
|Sun 19| 07:36a  06:17p  10:40 | 07:21p  06:32a |      Rise 03:07a   39%|
|Mon 20| 07:34a  06:18p  10:43 | 07:22p  06:31a |      Rise 03:59a   30%|
|Tue 21| 07:33a  06:20p  10:46 | 07:23p  06:29a |      Rise 04:49a   21%|
|Wed 22| 07:31a  06:21p  10:49 | 07:25p  06:28a |      Rise 05:34a   14%|
|Thu 23| 07:30a  06:22p  10:52 | 07:26p  06:26a |      Rise 06:16a    8%|
|Fri 24| 07:28a  06:24p  10:55 | 07:27p  06:25a |      Rise 06:54a    3%|
|Sat 25| 07:26a  06:25p  10:58 | 07:28p  06:23a |      Rise 07:29a    0%|
|Sun 26| 07:25a  06:26p  11:01 | 07:30p  06:21a |New   Set  06:43p    0%|
|Mon 27| 07:23a  06:28p  11:04 | 07:31p  06:20a |      Set  07:53p    2%|
|Tue 28| 07:21a  06:29p  11:07 | 07:32p  06:18a |      Set  09:03p    7%|
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Penumbral Lunar Eclipse February 10/11, 2016

Penumbral Lunar Eclipse

The moment of mid-eclipse at 7:45 p.m. February 10, 2016 EST (0:45 UT February 11). The Moon is traveling from upper right to lower left. Orientation is alt-az for northern Michigan. Created using Cartes du Ciel (Sky Charts).

In the early evening hours of February 10th the Moon will pass through the Earth’s outer or penumbral shadow.  It will not get particularly dark since the Moon will still be somewhat illuminated by the Sun.

Anything shows two types of shadows in the sunlight.  Your shadow appears fuzzy.  That fuzziness is your penumbra, where the sunlight is only partially blocked.  The dark inner part of your shadow is your umbra.

The eclipse starts at 5:34 p.m. (22:34 UT) at which time you will see nothing out of thee ordinary.  Since the Moon is entering the shadow at a shallow angle it will take 2 hours and 11 minutes to reach the maximum eclipse.  I’m guessing here, but one will probably not notice anything before 7 p.m.  (0:00 UT)  To help see the effect better, put on sunglasses.  They will reduce the Moon’s glare to help see the darkening effect.  Officially the eclipse will end at 9:53 p.m. (2:53 UT the 11th)

Binocular Comet 45P/Honda-Mrkos-Pajdusakova

Comet 45P

Comet 45P’s track for February. The comet is expected to be about a magnitude brighter than displayed (7th magnitude). Created using Cartes du Ciel (Sky Charts).

In the chart above the comet’s position is marked by a comet symbol. The comet’s tail, if visible at all, will actually point to the right along its track. The data for this chart is taken from Seiichi Yoshida’s Weekly Information about Bright Comets:

12/30/2016 – Ephemeris – Looking ahead at the eclipses of 2017

December 30, 2016 2 comments

Ephemeris for Friday, December 30th.  The Sun will rise at 8:19.  It’ll be up for 8 hours and 51 minutes, setting at 5:11.  The Moon, 1 day past new, will set at 6:53 this evening.

Looking ahead at astronomical events of the 2017.  There is one big one that all of us astronomers, both amateur and professional are looking forward to.  That is the total eclipse of the Sun on August 21st, where the center of the Moon’s shadow will sweep across the continental United States from Oregon to South Carolina.  The closest this path of totality will get to our area is around Carbondale, Illinois.  For the Grand Traverse area the Sun will be some 75% covered by the Moon.  As kind of a warm up event, we’ll have a slight eclipse of the Moon February 10th, where the Moon will enter the Earth’s outer partial shadow, nearly grazing the Earth’s inner shadow in the early evening.  It’s called a penumbral lunar eclipse.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.



February 10, 2017 Penumbral Eclipse of the Moon

This is the maximum of the February 10th penumbral lunar eclipse. The Moon will appear to move diagonally down to the left. It is shown at maximum eclipse at 7:45 p.m. (0:45 UT February 11). Created using Cartes du Ciel.

Shadows are, of course, invisible unless they are cast on an object, so the Moon would appear alone, though the upper left part of it would be noticeably dimmer than the opposite side.

August 21, 2017 Total Solar Eclipse Path of Totality

A screen cap of the map showing the path of totality of the August 21, 2017 total solar eclipse from NASA’s eclipse page. Credit: NASA and Google Maps.  Click on image to enlarge.

Click here to go to the page where this interactive map is located.  The magenta marker with GD is the point with the greatest duration of totality of 2 minutes 40.2 seconds.  The green marker with GE denotes where the Moon’s umbral shadow is the widest.  Clicking on any point on the map will pop a balloon shows all the eclipse information for viewing it from that place.  The partial eclipse can be seen from all fifty states, though in Hawai’i the Sun rises with the eclipse in progress.

Here in the Grand Traverse Region, the Moon will encroach on about 8/10ths of the Sun’s diameter, covering 75% of the Sun’s face.

Maximum eclipse in Traverse City

What the maximum eclipse would look like with proper filtering at Traverse City, MI. Created using Stellarium.

Eclipse Times for Traverse City

Eclipse Starts 12:58:03 p.m.
Maximum Eclipse 2:20:15 p.m.
Eclipse Ends 3:40:51 p.m.
Magnitude of the eclipse 0.798
Obscuration of the Sun 75.1%

Solar Corona

This is an inkling of what a totally eclipsed Sun looks like. No photograph can do it justice. Ya gotta be there! The solar corona displayed during the July 10, 1972* total solar eclipse from Prince Edward Island. Credit Bob Moler.

* Update:  Thanks for the heads up on the typo:

Program Note:

I’ve developed a PowerPoint slide presentation highlighting my four total eclipses and a look at future eclipses.  I will be happy to give this presentation to school groups and organizations free of charge except for mileage reimbursement over 50 miles.  Contact me at

December 31st – the longest day, really.

December 31st will be 24 hours and 1 second long.  This “leap second” will be added as the 61st second of the minute 6:59 p.m. EST (23:59 UT).  The reason is that the Earth’s rotation is slowing down ever so slightly, compared to the atomic clocks at the Bureau of Time.  There is some discussion of eliminating this leap second.  Most scientists want to use a constant time stream, and don’t give a hang about the rotation of the Earth.  The exact time which is also affected by special and general relativity is used by GPS navigation satellites.  A one second jump in time, at our latitude (45° north) is equivalent of the earth’s rotation of about two tenths of a mile.  I hope everyone’s coordinated on this.

03/22/2016 – Ephemeris – Really difficult lunar eclipse to spot at sunrise*

March 22, 2016 Comments off

Ephemeris for Tuesday, March 22nd.  The Sun will rise at 7:41.  It’ll be up for 12 hours and 17 minutes, setting at 7:58.   The Moon, 1 day before full, will set at 7:48 tomorrow morning.

The Paschal full moon is tomorrow morning.  I’ll explain more about it on Thursday as we get closer to Easter this coming Sunday.  However as the Moon sets for our region it will be in eclipse.  It’s not a big deal partial or total lunar eclipse, but a penumbral eclipse, where the Moon slips into the Earth’s outer shadow, where the Sun’s light is partially cut off by increasing amounts from the edge of the penumbra to the totally blocked umbral shadow.  As the Moon is setting tomorrow morning after 7:30 a.m., it may be showing a dusky lower left edge, the part of the Moon closest to the center of the Earth’s shadow.  It might difficult to see the effect, though the bright skies may actually help by washing out the light of the Moon.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

* The eclipse, such as it is, will not be visible east of us around 86º west longitude, and be more visible west of us.


Lunar Eclipse Geometry

How lunar eclipses occur. Credit NASA/Fred Espenak.

This eclipse, however the Moon will dip only into the outer penumbra.

March 23, 2016 penumbral eclipse of the Moon

The Eclipse diagram for the March 23, 2016 penumbral eclipse of the Moon. Credit Fred Espenak/NASA/GSFC.

Here’s a link to the original pdf of the image above.

Maximum eclipse will occur at 7:47 a.m. EDT (11:47 a.m. UT)

The Moon as it is about to set

What the progress of the eclipse is like at 7:40 a.m. The sky will be bright because the Sun will be rising at that time. Created using Cartes du Ciel (Sky Charts).

My 9/27/2015 lunar eclipse experience

September 28, 2015 Comments off

This is an elaboration of an email sent to a fellow amateur astronomer who was completely clouded out and asked how we did.

The Grand Traverse Astronomical Society decided to split our forces for the eclipse.  Some of us would be stationed at the Rogers Observatory, south of Traverse City; while the other would participate in an eclipse watch at the Sleeping Bear Dunes National Lakeshore about 30 miles to the northwest of Traverse City. For most of the week before the weather forecast was for clear weather.  Well it was not to be.  All day we were under low clouds streaming up from the southwest.
I headed the contingent that would join a park ranger at the spot in the park called the Dune Climb.  There was a mix up in the location of the watch.  I had it at a location 20 miles to the south.  So I went to that location and posted a sign about the change in venue and headed north to the Dune Climb.  On my way I ran into some misty rain.  Not exactly encouraging.  On the satellite images I was tracking all day Sunday the western edge of this big cloud system was over Lake Michigan.  I was hoping a weather system approaching from the northwest would push this cloud system out of the way.  It didn’t quite.
At the Dune Climb, we had reports from one of the visitors that they had seen the Moon from the town of Empire about 5 miles south of there.  That was before the eclipse started.  At about 9:15 the park ranger Peggy welcomed everyone and soon turned the mic over to me.  Two other members of the GTAS had arrived before me.  Don and Emmett.  Don would use the park’s 4 inch refractor.  Emmett brought his wonderful wooden 13 inch telescope on a Dobsonian mount on a Poncet platform.  Both telescopes would be deployed if the skies cleared.  I brought my telescope, but it turned out that I was spending too much time yakking to actually set it up.  With no Moon visible I ended up talking all about lunar eclipses, and what to expect if the Moon ever popped out of the clouds.  I talked about lunar eclipses, than turned to the solar eclipses I’ve seen and other topics in response to questions, for about an hour and a half.  At about 10:30 we noticed we could see stars to the low southwest over the dunes.  It took 15 minutes, but the hole in the clouds expanded and finally uncovered the Moon at about the mid-eclipse point.

From mid-eclipse, about 10:45, to  the end of totality it was almost perfectly clear,  We had light clouds after that to the end of the partial phase.  Then it clouded up again.  My impressions of the eclipse brightness at totality was that it was a bit darker than usual, but I may be wrong.  However I have had wretched luck in being able to view lunar eclipses.  We were virtually wiped out by clouds with the two lunar eclipses last year, and we’ve had the same luck for the many eclipses occurring before.  I may be out of practice.

The folks stationed at the Rogers observatory were indeed clouded out.  To paraphrase the crusader in Indiana Jones and the Last Crusade:  “We chose wisely.”  Or it was plain dumb luck.
Satellite cloud image

From the animation of the satellite images from Sunday night. The red circle points to the hole, really a notch in the clouds that allowed us to see the last part of the lunar eclipse.  Our low clouds were warm in the infrared so show as a very light gray. Credit NOAA/Environment Canada.