Posts Tagged ‘Solar Eclipse’

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.


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.

09/11/2015 – Ephemeris – Astronomy from the dark skies of the Sleeping Bear Dunes this Saturday

September 11, 2015 Comments off

Ephemeris for Friday, September 11th.  The Sun will rise at 7:16.  It’ll be up for 12 hours and 44 minutes, setting at 8:01.   The Moon, 2 days before new, will rise at 6:39 tomorrow morning.

Tomorrow night will be the next to the last Star Party at the Sleeping Bear Dunes National Lakeshore of the year.  It will be at the Dune Climb in the Parking lot nearest to the dunes.  Featured will be the wonders of the Milky Way including globular and galactic star clusters and planetary and emission nebulae.  The event starts at 9 p.m.  We are entering the second eclipse season of the year.

On Sunday there will be a partial solar eclipse visible from South Africa, the Southern Ocean and part of Antarctica.  Eclipses occur in no less a grouping than pairs, solar and lunar, the next eclipse is 16 days away.  It will be total lunar eclipse visible from here on Sunday evening the 27th.  In the week after next I’ll tell you all about it.

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


Star Party

Star Party at the Dunes Overlook. Credit: Eileen Carlisle. I still don’t have a good picture of a star party at the Dune Climb where the dune rises up and blocks the lower 20º of the western sky.

Partial Solar Eclipse

Partial Solar Eclipse of September 13, 2-15. Credit: NASA/GSFC/Fred Espenak.


07/20/2015 – Ephemeris – July 20th anniversaries

July 20, 2015 Comments off

Ephemeris for Monday, July 20th.  Today the Sun will be up for 15 hours and 5 minutes, setting at 9:21.   The Moon, 4 days before first quarter, will set at 11:34 this evening, and tomorrow the Sun will rise at 6:16.

July 20th is a special date for this country’s space program and a personal one.  On July 20, 1969 Apollo 11 landed on the Moon, the greatest achievement in the history of space flight.  Seven years later the robot lander Viking 1 landed on Mars.  NASA wanted it to be July 4th, 1976, the Bicentennial, but couldn’t find a smooth landing site in time.  My own connection to the date came in 1963, my first total solar eclipse. We traveled to Quebec province along side the St. Maurice River. To view 60 seconds of totality.  It was the first of four successful total solar eclipse trips I’ve been on..  I’m looking forward to my 5th on August 21st 2017, two years from now which is related to my first, I’ll tell you about that in my blog.

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


July 20, 1969

Neil Armstrong about to step off the LM onto the surface of the moon, July 20, 1969. Credit: NASA.

July 20, 1976

First image sent back from Viking 1 after landing on Mars, July 20, 1976. Credit: NASA/JPL.  Click on image to enlarge.

Video of July 20, 1963 eclipse from the air. I got only one picture of the eclipse and it wasn’t very good.

The date on the YouTube page is incorrect.  It is July 20, 1963.  I remember the corona being somewhat wedge-shaped, wider to one side than the other.  Other than that it was a typical quiet sun corona.

In the program above I mentioned that the August 21, 2017 solar eclipse was related to my first total solar eclipse.  This is the relationship:  A couple of centuries BC the Chaldean astronomers of ancient Babylonia discovered that eclipses repeated in a cycle lasting 6,585 1/3 days.  That’s 18 years 10 or 11 and 1/3 days depending on the number of leap years spanned.  That period was called the Saros by Sir Edmund Halley or comet fame.  So each eclipse would be visible 1/3 of the Earth farther west.  Note that there are many Saros cycles occurring at the same time, and that eclipses of a particular Saros gradually move northward or southward.  So to have an eclipse recur at the approximate same longitude one must wait 3 Saros cycles. or 54 years and one month approximately.  Thus the third Saros of the July 20, 1963 total solar eclipse will be August 21, 2017.  This Saros series (145) is moving southward.  In 1963 it crosses the US at Alaska and Maine.  Quebec was closer for us, s we went there.  Good thing too.  Maine was clouded and rained out.  For us the clouds parted at the beginning of the eclipse.  The 2015 eclipse will cross the continental US from Oregon to South Carolina.

A squished image of the July 20, 1963 eclipse path.  Right click on the image and select view image to get a correct image.  (works in Firefox).


A squished image of the August 21, 2017 eclipse path.  Right click on the image and select view image to get a correct image.  (works in Firefox).

10/22/2014 – Ephemeris – The bright planets this week plus a preview of Thursday’s partial solar eclipse

October 22, 2014 Comments off

Ephemeris for Wednesday, October 22nd.  The sun will rise at 8:06.  It’ll be up for 10 hours and 39 minutes, setting at 6:46.   The moon, 1 day before new, will rise at 7:46 tomorrow morning.

Tonight Saturn will be low in the west-southwest before it sets at 7:56 p.m.  Mars will be low in the southwest at 9 p.m. and will set at 9:40 p.m.  The sky will stay devoid of bright planets until Jupiter rises at 1:56 a.m. tomorrow morning.  Jupiter is visible this morning in twilight in the south-southeast along with the brighter stars of winter visible, a preview of colder evenings to come.  Tomorrow evening, weather permitting, we will get to see part of a partial solar eclipse.  The exact times depend on your location, though shouldn’t deviate from these by a few minutes for the Interlochen Public Radio listening area (northwestern lower Michigan).  The eclipse will start around 5:32 p.m. and will continue till sunset around 6:44 p.m.  Use proper eye protection or use pinhole projection.

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


Evening Planets

Saturn and Mars at 7:30 p.m. on October 22, 2014. Created using Stellarium.

Jupiter and the morning stars

Jupiter and the morning constellations at 6:30 a.m., October 23, 2014. Created using Stellarium.

Telescopic Jupiter

Jupiter through a telescope at 6:30 a.m. October 23, 2014. The unnamed moon is Io. Created using Stellarium.

Solar Eclipse coverage

Coverage of the partial solar eclipse of October 23, 2014. Credit: NASA.  Click image for more information.

Setting partially eclipsed sun

The setting partially eclipsed sun from Traverse City. Created using Stellarium.

Pinhole projection

Partially eclipsed sun using a series of pinholes projected on a reasonably white surface.

10/09/2014 – Ephemeris – The next lunar eclipses and recollections of what happened with yesterday’s eclipse

October 9, 2014 1 comment

Ephemeris for Thursday, October 9th.  The sun will rise at 7:50.  It’ll be up for 11 hours and 18 minutes, setting at 7:08.   The moon, 1 day past full, will rise at 8:01 this evening.

With the two total lunar eclipses done for this year, we can look forward to two more next year.  The April 4th, 2015 eclipse won’t appear total here because the moon will set before totality.  However the September 28th, 2015 lunar eclipse will be an evening eclipse.  These 4 eclipses make a rare tetrad of total lunar eclipses that won’t be repeated until 2032 and 2033.  After September 28th the next total lunar eclipse visible from northern Michigan will be in 2021.  On the solar eclipse side there’s one on the 23rd of this month, a partial eclipse at sunset.  I’ll have more on that later.  After that is the big event, the total solar eclipse on August 21, 2017.  The path of totality will run from coast to coast, running just south of St. Louis Missouri, and just north of Nashville Tennessee.

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


What follows is my recollection of the October 8th lunar eclipse.   Originally relayed in an email to Pat Stinson, freelance writer and author of the wonderful article in the Grand Traverse Insider about the activities of Space Week and the astronomical events in October:

The skies were trending clearer at midnight and again at 2:30 a.m. when I took a shower to prepare for the eclipse.  After that it got slowly worse. That afternoon Ranger Marie Scott of the Sleeping Bear Dunes National Lakeshore said she’d go to our site, Platte River Point, clouds or not, and I was willing.  In setting up the eclipse observing sites,earlier in the year, this site was the one place that if it were clear, we could see either the moon or the sun set onto the Lake Michigan horizon for the three eclipses this year.  I loaded my van with my two telescopes, the C8 and an 11″ Dobsonian and lots of coffee.

I got to the site at 4:30 and began to set up.  Marie arrived a few minutes later and another Grand Traverse Astronomical Society member Don Flegel arrived shortly after that.  They had some rain in Kingsley, where he lived that morning.  We had a strong, cold northwest wind.  When we’re at the Point we commandeer the small parking lot to the north of the road that’s up against a hill.  That hill and my van offered some protection from the wind.  I got the C8 set up just in time to spot the moon emerging from the clouds a few minutes after first contact.  We were able to follow the eclipse intermittently until about 5:45 when a large cloud covered the moon big time.  We could see the glint of the moon off the water until after totality.

This was our situation until about 7:30 when the clouds began to break up,  By then the moon was so low that the foreshortened breaks weren’t all that open.  Then about 10 minutes before moon set it did peek out at intervals.  Unlike the Cheshire Cat’s smile, the moon (cat) had a frown because the upper edge of the moon was coming back into sunlight.  5 minutes later the moon finally disappeared for good in a cloud bank as the puffy clouds overhead caught the sun’s golden sunrise rays.

Marie Scott counted 18 folks that at one time or another came out to witness the event.  Marie also posted some pictures she took of the eclipse on the park’s Facebook page.

09/30/2014 – Ephemeris – Previewing October skies and events

September 30, 2014 Comments off

Ephemeris for Tuesday, September 30th.  The sun will rise at 7:39.  It’ll be up for 11 hours and 45 minutes, setting at 7:24.   The moon, 1 day before first quarter, will set at 11:43 this evening.

Let’s look at the skies for the month of October.  The sun will still be moving south rapidly.  Daylight hours in the Interlochen/Traverse City area and will drop from 11 hours and 42 minutes tomorrow to 10 hours, 14 minutes at month’s end.  The altitude of the sun above the southern horizon at local noon will be 42 degrees tomorrow in the Interlochen area, and will descend to 31 degrees on Halloween.  This month will see two eclipses visible from our area plus a close encounter that a comet will have near Mars and our assets on and around Mars.  We will be able to see, weather permitting a total lunar eclipse in the morning a week from today, the 8th and a partial solar eclipse on the 23rd, just before sunset.

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


Star Chart

Star Chart for October 2014. Created using my LookingUp program.

The Moon is not plotted.  The planets and stars are plotted for the 15th at 8 p.m.  That is chart time.

Astronomical twilight ends at 9:00 p.m. on October 1st, decreasing to 8:11 on the 31st.

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

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

Also shown is the Summer Triangle in red. Clockwise from the top star is Deneb in Cygnus, Vega in  Lyra and Altair in Aquila.

The green pointers from the Big Dipper are:

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
  • The arc of the dipper’s handle points to Arcturus.

Information on the total lunar eclipse on the 8th will be posted starting Monday October 6th.

08/28/2014 – Ephemeris – The evening Moon will stay low in the sky for the next couple of weeks.

August 28, 2014 Comments off

Ephemeris for Thursday, August 28th.  The sun will rise at 7:00.  It’ll be up for 13 hours and 25 minutes, setting at 8:26.   The moon, 3 days past new, will set at 9:40 this evening.

Since we’re within a month of the autumnal equinox, coming up on September 22nd, something funny is happening with the Moon rise and set times near both new and full moon.  That is they aren’t changing very much.  Here we are with the Moon three days old, and it still sets before the end of astronomical twilight.  You may notice that for the next two weeks, that the Moon doesn’t get very high in the sky in the early evening.  It’s path stays close to the horizon.  Around first quarter next Tuesday the Moon will get to be just a little higher in the sky than the sun does on the first day of winter.  The next full moon is the Harvest Moon, being the full moon closest to the first day of autumn.  Then the day-to-day succession of rise times again will slow.

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


Low Moon

The Moon on September 3, 2014 a day after first quarter. It will rise higher after that if one stays up long enough. Created using Stellarium.  Click on image to enlarge.

In the image above the Moon’s orbit is compared to the ecliptic, the plane of the Earth’s orbit to which it’s inclined by about 5º.  Note the two points where these lines cross.  The point where the Moon’s orbit crosses the ecliptic heading northward is called the ascending node.  The crossing point heading southward is the descending node.  The important thing about that is the when the moon passes a node while at new or full, an eclipse will occur,  which they will do in October.  There will be a total lunar eclipse on the morning of October 8th, then a partial solar eclipse on October 23rd as the sun is setting here in northern Michigan.  I’ll have more information as the events gets closer.

01/06/2014 – Ephemeris – It will be a year of eclipses for northern Michigan!

January 6, 2014 1 comment

Ephemeris for Monday, January 6th.  The sun will rise at 8:19.  It’ll be up for 8 hours and 58 minutes, setting at 5:18.   The moon, 1 day before first quarter, will set at 12:07 tomorrow morning.

The year 2014 will be a year of eclipses.  World wide it will have the minimal number of eclipses possible, four.  However, lucky us, we will see three of them if it’s clear, that is.  The first is a total eclipse of the moon in the wee morning of Tax Day, April 15th.  It will be the best of the three because we will see it from beginning to end.  On October 8th we will have another lunar eclipse is the morning.  This one will start closer to dawn, so the kids can see this one by getting up early.  The total phase will be visible, but the moon will set as the moon is leaving the earth’s shadow.  The last will be a partial solar eclipse on October 23rd. when the eclipse will be interrupted by sunset.

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


My Article in January’s Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society.

After a drought in visible eclipses seen from our part of the planet last year and a single partial solar eclipse the year before, we have a chance, weather permitting, to view two total lunar eclipses and the first half of a partial solar eclipse this year. OK, we did have a penumbral lunar eclipse last year, but I usually don’t count penumbral eclipses, since the casual observer may look at the moon and not know they are occurring.  They’re what I call a 5 o’clock shadow eclipse, where parts of the moon are illuminated by a partially blocked sun.  There is no obvious dragon or Cookie Monster nibbling at the moon.

Eclipse Seasons

In 2014 the two eclipse seasons are in April and again in October.  These are about six months apart centered around the moon’s ascending and descending nodes, where the plane of the Moon’s orbit crosses the Earth’s orbital plane when the new moon’s shadow can fall upon the earth and the earth’s shadow can fall on the full moon.
The line of nodes regresses westward or clockwise slowly in an 18.6 year period.  That means that the eclipse seasons slowly move backward through the calendar.  Every time the sun passes a node there are either two or rarely, three eclipses.  Either one each of lunar and solar separated by two weeks from the other.  Or, rarely, a central eclipse with 2 weeks before and two weeks later a very partial eclipse near the poles in the case of solar eclipses or penumbral eclipses in the case of lunar eclipses.  2014 is a year of two total lunar eclipses and two partial solar eclipses near the poles.


A means of predicting eclipses was developed by the Chaldeans in what is now Iraq some centuries before the common era (BC or BCE).  The Greeks learned of it.  Hipparchus and Ptolemy knew of it.  Solar and lunar eclipses repeat every 18 years 11 1/3 days.  This cycle was called the Saros by Sir Edmund Halley of Halley’s Comet fame, then Astronomer Royal in England.
The saros is the near coincidence of 3 lunar “months”:  the Synodic Month, or lunation the period between new moons; the Draconic Month, the period between the moon’s passage of the ascending node of its orbit as explained above; and the Anomalistic Month, the period between passages of the moon through perigee, the closest point in its orbit to the earth.
The synodic month is on average 29.530589 days, and the basis for the Jewish and Islamic lunar calendars.
The draconic month is 27.212220 days long on average.  The ascending node regresses westward, so meets the moon, traveling eastward than the synodic month, where it has to catch up with the eastward moving sun.  Remember the dragon eating the sun image from above. The ancients thought a dragon lived at the nodes to devour the Sun or Moon in eclipses.  The symbol for the ascending node:DragonsHeadis called the Dragon’s Head. For the descending node the symbol is inverted and called the Dragon’s Tail. These symbols may be seen on orbital diagrams.
The anomalistic month is 27.554551 days.  In celestial mechanics an anomaly doesn’t means anything is wrong, it’s the angle between, in the case of the moon, the perigee of its orbit and the position of the moon as seen from the earth.  It has to do with the perigee and that’s why it’s used.
It turns out that:
223 Synodic Months = 6585.322 days
242 Draconic Months = 6585.8 days
239 Anomalistic months = 6585.5 days
Thus the Saros cycle is 6585.322 days long, or 18 years 11 1/3 days, meaning that the next eclipse of that Saros occurs a third of the earth in longitude west of the previous eclipse.  It takes three saros cycles for an eclipse to repeat near the same longitude.  For instance, my first total solar eclipse was viewed from Quebec on July 20, 1963. The third Saros of that eclipse will occur on August 21, 2017.  I expect to be around to see that, my 5th total solar eclipse.  The path will shift southward and be seen across the continental United States.
There are something like 40 Saros cycles active at one time.  Eclipses at the descending node head southward each eclipse, while those at the ascending node move northward.

The Eclipses of 2014

Here are the dates of the eclipses:
Total Lunar Eclipse April 15, 2014
Total Lunar Eclipse October 8, 2014
Partial Solar Eclipse October 23, 2014
Interestingly, all these eclipses will occur in the western part of the sky for us in northern Michigan.  Both October eclipses will end with the eclipsed body setting before the official end of the eclipse.  This means that both lunar eclipses are early morning eclipses and the solar eclipse will be a late afternoon eclipse.
Lunar eclipses start and end with the moon traveling through the earth’s penumbral shadow.  It’s been my experience that this shadow only becomes visible in the half hour before and after the partial phases of the eclipse. The partial phase of the Tuesday April 15th lunar eclipse will start at 1:58 a.m., totality starts at 3:06 and ends at 4:24; with the partial phase ending at 5:33 as twilight begins to brighten.
The Wednesday October 8th lunar eclipse will start later in the morning.  The partial phase will start at 5:14 a.m. Totality will run from 6:25 to 7:24 a.m. all in the growing morning twilight.  Sunrise and moonset will interrupt the eclipse by 7:57.
The partial solar eclipse is on Thursday October 23.  The eclipse will begin around 5:33 p.m. for Traverse City with sunset at 6:44.  Times and whether the eclipse is visible at all depend on the location of the observer.

NASA diagrams, maps, and more information on these eclipses can be found here.

12/27/2012 – Ephemeris – That was the year that was.

December 27, 2012 Comments off

Ephemeris for Thursday, December 27th.  The sun will rise at 8:18.  It’ll be up for 8 hours and 50 minutes, setting at 5:09.   The moon, 1 day before full, will set at 8:10 tomorrow morning.

The end of the year is the perfect time to look back at the astronomical events of the year.  There was a partial solar eclipse in May and the rare transit of Venus across the sun in June.  You’ll have to wait until 2117 for the next one.  In July came news that the Large Hadron Collider had detected something that sure looked like the long sought Higgs Boson.  August brought the spectacular landing of the Mars Science laboratory, aka: The Curiosity rover, on Mars to begin an at least one martian year exploration.  In September the Dawn spacecraft bid farewell to the asteroid Vesta after a year exploring that remarkable asteroid, cranking up its ion engine for a three year journey to the dwarf planet Ceres.  The satellites Ebb and Flow completed their mission to map the moon’s interior.

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


Hinode Views the 2012 Venus Transit

Hinode Views the 2012 Venus Transit. Credit: JAXA/NASA/Lockheed Martin

Simulated Higgs event

An example of simulated data modeled for the CMS particle detector on the Large Hadron Collider (LHC) at CERN. Here, following a collision of two protons, a Higgs boson is produced which decays into two jets of hadrons and two electrons. The lines represent the possible paths of particles produced by the proton-proton collision in the detector while the energy these particles deposit is shown in blue. Credit CERN.

Curiosity rover self portrait.

Curiosity rover self portrait. Credit: NASA/JPL-Caltech/Malin Space Science Systems

Vesta as Dawn headed off to Ceres.

Looking back at Vesta as Dawn headed off to Ceres. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

The Grail Spacecraft Ebb and Flow

The Grail Spacecraft Ebb and Flow made the most detailed gravitational map of the moon to map its interior; orbiting as close as 15 miles above the surface. They were intentionally crashed into a crater wall on December 17th. Artist conception credit: NASA.

11/13/2012 – Ephemeris – Total Solar Eclipse in the South Pacific

November 13, 2012 Comments off

Ephemeris for Tuesday, November 13th.  The sun will rise at 7:37.  It’ll be up for 9 hours and 39 minutes, setting at 5:16.  The moon is new today, and won’t be visible.

There will be a total solar eclipse today for the South Pacific Ocean.  The path of totality crosses almost no land except in the two northernmost tips of Australia.  Australia, New Guinea, New Zealand parts of Antarctica, Chile and Argentina will get a partial eclipse.  The moon’s shadow crosses the earth from west to east, so in crossing the International Date Line it will start at sunrise on November 14th local time and end at sunset November 13th local time.  The solar eclipse we’re waiting for is the total solar eclipse of August 21st 2017, now less than 5 years away.  This will be at least partial for the contiguous 48 states with the path of totality crossing the central United States.  Being in the path of totality that day is high on my bucket list.

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


Diagram of the coverage of the November 13-14 total Solar Eclipse.  Courtesy Fred Espanek, NASA.

Diagram of the coverage of the November 13-14 total Solar Eclipse. Courtesy Fred Espanek, NASA.

Here’s an animation that brings the above chart to life.

November 13-14 total solar eclipse animation.  Courtesy NASA, A. T. Sinclair.

November 13-14 total solar eclipse animation. Courtesy NASA, A. T. Sinclair.