Category Archives: eclipse

Transit of Mercury, November 11, 2019

Monday morning in North America, there will be visible a transit of Mercury. The innermost planet will pass directly between the sun and Earth, and will be visible as a small black dot.

The event will begin at 7:35 AM Eastern Time, 6:35 Central Time. Mercury will be at the centermost part of the sun at 10:20 Eastern, 9:20 Central. The event ends at 1:04 PM Eastern, 12:04 PM Central. Local sunrise in Minneapolis is at 7:05 AM, and I”m hopeful that it will be visible in the rising sun. I’m told that Mercury is too small to be visible with the naked eye, but I’m hoping that the sun’s low position on the horizon will make the small speck visible.

Even though the sun will be low on the horizon, you will need eye protection. So dig out those eclipse glasses that you acquired for the 2017 eclipse. If you are unable to view it, it will be live streamed from the University of Minnesota:

Solar Eclipse of August 7, 1869

Philadelphia Evening Telegraph, Aug 4, 1869.

Today marks the 150th anniversary of the total solar eclipse of August 7, 1869. The path of totality started in Asiatic Russia, and covered a tiny swath of China and much of Siberia before crossing the Bering Strait into Alaska and Yukon, and then through parts of the present day provinces and states of British Columbia, Alberta, Saskatchewan, Montana, the Dakotas, Minnesota, Iowa, Nebraska, Missouri, Illinois, Kentucky, Tennessee, Virginia, West Virginia, and the Carolinas.

The eclipse wasn’t the first to be photographed. Those honors go to the eclipse of July 28, 1851, which, according to Wikipedia, produced the first scientifically usable photograph. It does have the distinction of being the first to provide detailed spectroscopic images of the corona, which revealed an element believe for many years to be “coronium“. It took 70 years to realize that the spectrographic line was not a new element, but instead iron at over a million degrees Kelvin. The image shown above left was prepared by Prof. Charles Augustus Young of Dartmouth College, who was part of a team at Burlington, Iowa. The same team produced the photo shown below:

Another team left Burlington for Ottumwa, Iowa, but was beset by problems. They had forgotten their chronometer in Burlington, and the telescope clockwork was damaged in transit. Notwithstanding these difficulties, they managed 34 photographs, including four of totality, one of which is shown at left.

Another team was headed by Prof. William Harkness of the U.S. Naval Observatory. This team constructed a temporary observatory at the northwest corner of Second and Short Streets in Des Moines. Harkness reported that this vacant property on the west bank of the Des Moines River had a horizon almost devoid of obstructions. “Short Street” no longer exists, but according to the 1869 Des Moines city directory, it ran from the Des Moines River to Third Street (only a little more than a block, hence the name). From the description of the observatory being on the west bank, it would appear that the building was near the current site of Wells Fargo Arena.

A local contractor, one F.T. Nelson was retained to build the structure, shown at right. This team also obtained multiple photographs and spectrograms. The sketch below is the eclipse as seen through their four inch telescope.

Carptenter F.T. Nelson’s listing in the 1869 city directory.

The August 13, 1869, issue of the Cedar Falls (IA) Gazette carried this account of the eclipse. Those of us who witnessed the 2017 eclipse concur in the accuracy of this report. Indeed, from our viewing point in Hastings, Nebraska, we also had the added tension that “the forenoon was slightly hazy, but it cleared away and left no obstruction while the eclipse was passing.”

THE TOTAL ECLIPSE

Its Appearance in Cedar Falls

Government Observations.

Report of the Party, &c., &c.

It is not often that an opportunity is offered to witness so wonderful an exhibition of nature as the eclipse of Saturday last. Those who witnessed this extraordinary spectacle intelligently, will never forget its impression. It excites the most lively feelings of awe and wonder, and a breathless intensity takes possession of one as he gazes upon this grand movement in the heavens. The sight certainly gives one, a clearer view of the infinite majesty and power of the Great Being, and seems to speak directly to us of His greatness. The day was favorable, the forenoon was slightly hazy, but it cleared away and left no obstruction while the eclipse was passing.

The parties of observations were quite successful. Cedar Falls was made one of the points of observation by the Government, and will hereafter be one of the points from wliich calculations will be made. The party sent out by the Government to take observations iu this city were Ed. W. Horr, son of Dr. Horr of the Smithsonian Institute, and Wm. I. Anderson and W. W. Wormood, of Dubuque.

References

South American Eclipse of 2 July 2019

In preparation for the total solar eclipse of 2 July 2019, which will be visible in Chile and Argentina, I have updated and translated into Spanish my “Take Your Kids To See The Eclipse” page. You can view the 2017 English version at this link.

En preparación para el eclipse solar total del 2 de julio de 2019, que será visible en Chile y Argentina, actualicé y traduje al español mi página “Lleve a sus niños a ver el eclipse”. Puedes ver la versión de 2017 en inglés en este enlace.

Einstein and the Eclipse of 1919

Eclipse as seen on Principe. Wikipedia photo.

Today marks the 100th anniversary of the eclipse of May 29, 1919. The total solar eclipse, which darkened the skies over a band from South America to Africa, had the distinction of having the longest totality (6 minutes 51 seconds) of any since 1416.

Einstein in 1921. Wikipedia image.

But the eclipse was most notable as making possible an experiment that demonstrated one of the predictions of Albert Einstein‘s General Theory of Relativity published in 1915. The gravitational pull of a large object (such as the sun) would bend light waves passing close by, and Einstein predicted how large the effect would be. He noted that a solar eclipse would be the perfect opportunity to prove or disprove the theory, since stars close to the sun would be visible. Their “correct” location in the sky was known. If they could be observed in the “wrong” location, then the measured location would confirm his theoretical findings.

The first attempt was done in conjunction with the eclipse of August 21, 1914. An expedition made up of German and U.S. astronomers traveled to Crimea to observe the eclipse. Unfortunately, Germany declared war on Russia on August 1. The German scientists were either sent home or taken prisoner. The U.S. astronomers were not detained, but clouds prevented the necessary observations.

Dyson (left) and Eddington (right). (Photo credit.)

The 1919 eclipse was the next opportunity, and an experiment was organized by British astronomers Frank Watson Dyson and Arthur Stanley Eddington. This came to be known as the Eddington experiment. Rather than place all eggs in the same basket, as happened in Crimea, the 1919 experiment would have observations taken at two sites: Sobral, Brazil, and the island of Principe off the west coast of Africa.

In Principe, even though clouds obscured the sun until shortly before the eclipse, the team was able to make several photographic plates, one of which showed the background stars clearly enough. The positions did confirm Einstein’s predictions.

While the scientific community was slow to fully accept the findings, the popular press jumped on board, and Einstein’s name became a household word as a result of the experiment. The news clipping below, for example, calling the experiment “the greatest discovery in history” appeared in the Washington Times on November 9, 1919.

Eclipse of April 8, 2024

2024 Eclipse Path. NOAA image.

As we did in 2017, OneTubeRadio.com will provide full coverage of the April 8, 2024, total solar eclipse.

This is exactly five years from today. Little preparation is needed at this point, but you should make a mental note to travel to the path of totality, which is less than a days’ drive from most of the United States. The total eclipse will be visible in parts of Texas, Oklahoma, Arkansas, Missouri, Illinois, Indiana, Ohio, a tiny piece of Michigan, Pennsylvania, New York, Vermont, New Hampshire, and Maine. The path of totality also passes through Mexico and Canada. Major cities in the path of totality include Dallas, Little Rock, Indianapolis, Buffalo, Cleveland, and Montreal.

The eclipse will take place on a Monday. For the 2017 eclipse, we made our hotel reservations about a year in advance, and paid the normal rate with plenty of availability. So if you plan on booking in April 2023, you should have many options. Also, in late 2023 or early 2024, you should order your eclipse glasses.

If you have kids who will be in school, plan on taking them out of school that day. Unfortunately, the 2017 eclipse showed that American schools had an irrational fear of the eclipse and actively prevented children from witnessing it. If you believe that your child’s school is more enlightened, then on the first day of the 2023-24 school year, you should have your children ask the science teacher if the school is planning a field trip to see it. If the teacher balks, then your children should let him or her know that they will be absent the day of the eclipse.

This is an entirely reasonable request for most schools. For example, students in Chicago could be placed on a school bus and taken to see the eclipse only a couple of hours’ drive away in Indiana. The expense will be less than other field trips taken to amusement parks, movies, etc. This is true for schools in many cities. They have the opportunity to let the kids witness an amazing scientific event, but only if they do some basic planning.

But I predict that this won’t happen, since most schools won’t think of the possibility until after it’s too late to make the necessary plans, or they’ll have the same irrational fears that showed up in 2017. It’s the duty of the students to pester the administration so that the necessary plans are made sufficiently in advance. And as I explained in 2017, if the school fails to act, then it’s reasonable for children to skip school on April 8, 2024.

Solar Eclipse of February 26, 1979

1979 eclipse as seen in Bozeman, Montana. Wikipedia photo.

Today marks the 40th anniversary of the solar eclipse of February 26, 1979. The path of totality passed through Washington, Oregon, Idaho, Montana, and North Dakota before entering Saskatchewan, Manitoba, Ontario, Quebec, and the Northwest Territories. From Canada, the path of totality entered the north Atlantic before ending in Greenland.

The path through Winnipeg, Manitoba, was tantalizingly close to my home in Minnesota, but I was unable to travel to see the spectacle. I had to settle for 90% coverage (in other words, millions of times more sunlight) where I was. I did vow that I would see the next one, in 2017, and I did.

This video shows coverage of the eclipse as totality passed through Winnipeg:

Lunar Eclipse, January 20, 2019

NASA image.

While not nearly as spectacular as a solar eclipse, another interesting astronomical phenomenon will be visible this Sunday evening throughout the Western Hemisphere. This will be a lunar eclipse, in which the moon passes through the shadow of the earth.

The eclipse begins at 9:36 PM Eastern Time (8:36 CST, 7:36 MST, 6:36 PST) with the penumbral phase, as the moon enters the outer shadow of the earth. The brightness of the moon will decrease, but the small change in brightness probably won’t be visible to the naked eye.

About an hour later at 10:33 PM Eastern Time (9:33 CST, 8:33 MST, 7:33 PST), the eclipse enters the partial stage. At this time, the earth’s shadow begins to eat away at the moon. This continues until 11:41 PM Eastern Time (10:41 CST, 9:41 MST, 8:41 PST), when the eclipse becomes full, and the moon is completely within the shadow of the earth.

Unlike a solar eclipse, the times are more or less identical wherever you are. You only need to adjust for your time zone.

Image result for lunar eclipse site:nasa.gov Even though the eclipse is full, the moon does not become fully dark. This is because the moon is illuminated by a ring surrounding the earth, namely, all of the sunrises and sunsets taking place on earth.

At 12:43 AM Eastern Time, the eclipse once again becomes partial. At 1:50 AM Eastern Time, it re-enters the penumbral phase. At 2:48 AM Eastern Time, the eclipse ends.

We previously wrote of an interesting story of a lunar eclipse of July 15, 1916. This eclipse affected the Shackleton Antarctic expedition. The team led by Aeneas Mackintosh was waiting for a full moon to embark, but were surprised to see the moon entering an eclipse as it rose. Fortunately, the eclipse was only partial and enough light remained to make the voyage.

NBC Radio, Canton Island Eclipse Coverage, 1937

This picture appeared in an RCA advertisement in Life magazine 80 years ago today, September 5, 1938. It shows NBC engineers Marvyn Adams and W.R. Brown along with NBC announcer George Hicks broadcasting live from Canton Island (sometimes spelled Kanton) in the South Pacific.

1937 Eclipse from Canton Island. Wikipedia image.

They were on the island as part of a joint expedition by the U.S. Navy and the National Geographic Society for the solar eclipse of June 8, 1937. The NBC eclipse coverage was transmitted from this “ultra-high frequency transmitter” to the USS Avocet anchored at the island, and from there to the RCA station at Point Reyes, California, where it went by wire to the NBC Blue Network.

According to the ad, the island would possibly “play an important role in transpacific air transport service,” a prophecy which proved true, as the island served as a stop for PanAm’s Pacific Clipper service to New Zealand, which ran from 1940 until the war, and then again from 1946.

The Navy-National Geographic expedition, in addition to observing the eclipse, placed a monument on the island to bolster the U.S. claim to sovereignty over the island. This was disputed by the British, who also had a ship anchored for the eclipse. Reportedly, the British ship, the HMS Wellington, fired a shot across the bow of the USS Avocet, which reciprocated. The two commanders called a truce pending further instructions from their command, and the two parties observed the eclipse together.

During the war, the U.S. Navy built a 6230 foot airstrip on the island, which was defended by as many as 1200 combat forces, but was never attacked by Japan. The island now forms part of the Republic of Kiribati. As of 2010, it had a population of 24.

The island was most recently in the news that year after a yacht stopped en route from Honolulu to Fiji and discovered that the islanders were desperately short of food, an expected supply ship never having arrived. The islanders had been living on fish and coconuts for several months, and the yacht owner used his satellite phone to contact the U.K. Coast Guard, which contacted the U.S. Coast Guard to arrange relief supplies.

1952 and 1954 Solar Eclipses

Millions of Americans were able to witness the Great American Eclipse of 2017 or will be able to see the eclipse of April 8, 2024. The 2017 eclipse crossed the United States from northwest to southeast, and the 2024 eclipse will run from southwest to northeast. The Soviet Union had a similar pair of eclipses on 25 February 1952 and 30 June 1954. The intersection of the two American eclipses is near Carbondale, Illinois. The paths of the two Soviet eclipses had their intersection at a point in northern Iran, just south of the Caspian Sea.

SovietEclipseMap

The illustrations shown here are from a Soviet booklet published in 1950. In addition to discussing solar and lunar eclipses generally, it contains information about the two Soviet eclipses of the 1950’s, including the map shown above. It also contains a table showing all total solar eclipses worldwide through 1999.

Prof. Mikhailov. Institute of Astronomy, Russian Academy of Sciences photo.

The booklet, Солнечные и лунные затмения (Solar and Lunar Eclipses) by Prof. A.A. Mikhailov, part of the series Научно-популярная библиотека (Popular science library), reveals that the path of the 1954 eclipse came very close to a number of Soviet cities, including Kaliningrad, Vilnius, Minsk, Kiev, Rostov, and Baku. The 1954 eclipse had also been visible in the United States, starting at sunrise in Nebraska, and passing over South Dakota and Minnesota (including Minneapolis and St. Paul). It then passed over Canada, Greenland, a tiny portion of Iceland, Norway, and Sweden, before entering the Soviet Union near Kaliningrad.

The 1952 eclipse, after passing over Africa, went over a less populated area of Turkmenistan, Uzbekistan, Kazakhstan, and Asiatic Russia.

This video shows the 1954 eclipse from Minneapolis:

This page contains a reminiscence and photo of the same eclipse from Kiev. The Google translate function does an admirable job of making it readable in English.

One of the scientific observations made during the 1954 eclipse was the measurement of radio emissions by the sun on various frequencies, documented in this 1955 article in the journal Astrophisica Norvegica, vol. 5, p. 131. The graph below shows the signal as received in Vesterøya, Norway, on 200 MHz. As would be expected, the solar noise reaches a minimum value at the time of total eclipse.

Information on how to form a Minnesota LLC.

What to Do With Your Used Eclipse Glasses

Now that the eclipse is over, you probably have eclipse glasses that you don’t need. You might want to save at least one pair, since you can use them to view sunspots, to view the transit of Mercury* on November 11, 2019, or even to view the International Space Station when it crosses in front of the sun*. You can also save them, of course, for the next eclipse in 2024.

Update: See the important note at the end of this post before attempting to view the transit of Mercury or the transit of the ISS.

However, you might want to get them into the hands of someone else who can use them to view an eclipse. One option is to send them to Astronomers without Borders, which is collecting used glasses, and will distribute them to persons in other parts of the world before upcoming eclipses. You can find instructions at their website.

However, you can just as easily cut out the middleman. Astronomers Without Borders will need to sort the glasses and distribute them. You can just as easily send them directly to someone who can use them. It will only cost you $1.15, which is the international postage rate for up to one ounce, which is enough for two sets of glasses and a letter explaining what they are.

Coverage ofl eclipse of 15 Feb. 2018. Wikipedia, by Fernando de Gorocica - Own work, CC BY-SA 4.0.

Coverage of eclipse of 15 Feb. 2018. Wikipedia, by Fernando de Gorocica – Own work, CC BY-SA 4.0.

The next eclipse will take place on February 15, 2018. This will be a partial eclipse that will be visible in Chile and Argentina. It will just barely be visible in Buenos Aires, but the sun will be about 40% covered in southern Chile and Argentina, in Tierra del Fuego.

Argentina and Chile will also have two total eclipses, in 2019 and 2020. Therefore, it makes sense to get students in southern Argentina and Chile excited about the partial eclipse in February. After they see the partial eclipse in 2018, they will have time to make plans to go see the total eclipses in 2019 or 2020, just like we did in 2017.

It’s not hard to do. All you need to do is find the name and address of a school in southern Argentina or Chile. Then, you send them one or two pairs of glasses, along with a letter explaining what the glasses are for.

Here’s a sample letter in Spanish. You can simply cut and paste this letter into your word processor. If you want, you can add your name, address, and e-mail. Or if you prefer, you can just send an anonymous gift.

Estimados [NAME OF SCHOOL]:

Encontré su nombre y dirección en Internet, y me gustaría presentarle este pequeño regalo. Éstos son lentes especiales que se pueden utilizar para ver con seguridad el sol durante un eclipse solar.

Hubo un eclipse solar total en los Estados Unidos el 21 de agosto de 2017, y vi esta espectacular vista en el estado de [STATE WHERE YOU SAW THE ECLIPSE]. No habrá otro eclipse solar en los Estados Unidos hasta 2024. Habrá eclipses en Argentina y Chile en 2018, 2019 y 2020. El proximo eclipse, un eclipse parcial, será el 15 de febrero de 2018 en el sur de Argentina y Chile. Por lo tanto, los estadounidenses han sido alentados a enviar sus gafas de eclipse a escuelas u organizaciones en Argentina o Chile. Estos lentes se volvieron difíciles de encontrar en los Estados Unidos antes del eclipse, y queremos asegurarnos de que tantas personas como sea posible tengan gafas para ver los próximos tres eclipses.

Hay más información sobre el eclipse y sobre estas gafas en el siguiente sitio de internet:

http://OneTubeRadio.com/gafas/

Esperamos que disfrute viendo los próximos eclipses tanto como disfrutamos del nuestro.

En amistad,

Here’s a translation in English:

Dear [NAME OF SCHOOL]
I found your name and address on the internet, and would like to present you with this small gift. These are special glasses that can be used to safely view the sun during a solar eclipse.

There was a total solar eclipse in the United States on August 21, 2017, and I viewed this spectacular sight in the State of [STATE WHERE YOU SAW THE ECLIPSE]. There will not be another solar eclipse in the United States until 2024. There will be eclipses in Argentina and Chile in 2018, 2019, and 2020. The next eclipse, a partial eclipse, will be on 15 February 2018 in the south of Argentina and Chile. Therefore, Americans have been encouraged to send their eclipse glasses to schools or organizations in Argentina or Chile. The glasses became hard to find in the United States before the eclipse, and we want to make sure as many people as possible have glasses to view the next three eclipses.

There is more information about the eclipse and about these glasses at the following website:

http://OneTubeRadio.com/gafas/

We hope you enjoy viewing the next eclipses as much as we enjoyed ours.

In friendship,

Or, if you prefer, you can write your own letter, either in English or Spanish. Even if your letter is in English, someone will be able to read it. The letter includes a link to a page on this site, and that page includes more information in Spanish, along with links to other sites with information about the upcoming eclipses.

It’s easy to find the name of a random school to send the glasses to. Just go to Google Maps, and zoom in on southern Argentina or Chile. Find the name of a town. Then, Google the name of that town along with the word “escuela” or “colegio.” Look through some of the results, and you’ll find the website of a school. Look for their address on their website. Put the glasses in an envelope with $1.15 postage, and put them in the mail.

A high school in Arkansas also needs a few samples of various brands of eclipse glasses. You can see more details at this Facebook post to see if they still need a sample of your brand.

Update: I’ve been informed that it’s not possible to see the transit of Mercury or the transit of the ISS with the naked eye. Of course, it doesn’t hurt to try, as long as you have your trusty eclipse glasses on. But whatever you do, don’t try to kludge something together to use binoculars or a telescope in conjunction with your glasses. If the glasses are at the end near your eyes, then there’s a real possibility that the magnified rays of the sun will burn a hole in the glasses, followed quickly by a hole burnt into your eyeball, which is not a good thing. Putting the glasses on the other end of the telescope or binoculars isn’t quite as dangerous, but it’s still a really bad idea.

The person who brought this to my attention was concerned that someone would attempt to do these things, that they would do them in an unsafe manner, and they would then sue me. You can, of course, sue anyone at any time for any reason. But the lawsuit would almost certainly be unsuccessful, as explained in this case.