Solar eclipse of August 21, 2017

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Solar eclipse of August 21, 2017
Type of eclipse
Nature Total
Gamma 0.4367
Magnitude 1.0306
Maximum eclipse
Duration 160 sec (2 m 40 s)
Coordinates 37°00′N 87°42′W / 37°N 87.7°W / 37; -87.7
Max. width of band 115 km (71 mi)
Times (UTC)
(P1) Partial begin 15:46:48
(U1) Total begin 16:48:32
Greatest eclipse 18:26:40
(U4) Total end 20:01:35
(P4) Partial end 21:04:19
Saros 145 (22 of 77)
Catalog # (SE5000) 9546

A total solar eclipse will take place on Monday, August 21, 2017. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometers wide.

This eclipse is the 22nd of the 77 members of Saros series 145, the one that also produced the solar eclipse of August 11, 1999. Members of this series are increasing in duration. The longest eclipse in this series will occur on June 25, 2522 and last for 7 minutes and 12 seconds.


The eclipse will have a magnitude of 1.0306 and will be visible from a narrow corridor through the United States. The longest duration of totality will be 2 minutes 41.6 seconds at 37°38′12″N 89°15′24″W / 37.63667°N 89.25667°W / 37.63667; -89.25667 in Makanda Township just south of Carbondale, Illinois.[1] It will be the first total solar eclipse visible from the southeastern United States since the solar eclipse of March 7, 1970.

A partial solar eclipse will be seen from the much broader path of the Moon's penumbra, including all of North America, northern South America, western Europe, and Africa.

Related eclipses over the United States[edit]

Detailed map of the path in the USA

This eclipse will be the first total solar eclipse visible from the United States since 1991 (which was seen only from part of Hawaii),[2] and the first visible from the contiguous United States since 1979.[3] A 1991 article in Discover noted that "The total solar eclipse of July 11, 1991", that passed over Hawaii and significant portions of Mexico, "[was] the best anyone will be able to see from the [US land] until 2017."[4]

The path of totality of the solar eclipse of February 26, 1979 passed only through the states of Washington, Oregon, Idaho, Montana, and North Dakota. Many visitors traveled to the Pacific Northwest to view the eclipse, since it was the last chance to view a total solar eclipse in the United States for almost four decades.[5][6]

Some American scientists and interested amateurs seeking to experience a total eclipse participated in a four-day Atlantic Ocean cruise to view the solar eclipse of July 10, 1972 as it passed near Nova Scotia. Organizers of the cruise advertised in astronomical journals and in planetarium announcements emphasizing the lack of future U.S. total eclipses until this 2017 event.[7]

The August 2017 eclipse will be the first with a path of totality crossing the USA's Pacific coast and Atlantic coast since 1918.

The path of this eclipse crosses the upcoming path of the total solar eclipse of April 8, 2024, with the intersection of the two paths being in southern Illinois in Makanda Township at Cedar Lake just south of Carbondale. A small land area, including the cities of Makanda, Carbondale, Cape Girardeau, Missouri, and Paducah, Kentucky, will thus experience two total solar eclipses within a span of fewer than seven years.

The solar eclipse of August 12, 2045 will have a very similar path of totality over the USA, about 400 km (250 mi) to the southwest, also crossing the USA's Pacific coast and Atlantic coast; however, duration of totality will last over twice as long.[8]

An eclipse of comparable length (up to 3 minutes 8 seconds) occurred over the contiguous United States on March 7, 1970 along the southeast US coast, from Florida to Virginia.[9]

The Eclipse in Europe[edit]

The boundaries of the sunset partial eclipse in Europe. Calculation with EclipseDroid with atmospheric refraction.

In northwestern Europe, the eclipse will only be visible as a partial eclipse, in the evening or at sunset. Only Iceland, Scotland and Ireland will see the eclipse from beginning to end, in the the rest of the UK, Norway, the Netherlands, Belgium, France, Spain and Portugal sunset will occur before the end of the eclipse. In Germany, only in the extreme northwest the beginning of the eclipse might be visible just at sunset. In all regions east of the orange line in the map the eclipse will be invisible.[10]


Related eclipses[edit]

A partial lunar eclipse will take place on August 7, 2017.

Solar eclipses 2015–2018[edit]

Each member in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.

Saros series 145[edit]

This solar eclipse is a part of Saros cycle 145, repeating every 18 years, 11 days, containing 77 events. The series started with partial solar eclipse on January 4, 1639, and reached a first annular eclipse on June 6, 1891. It was a hybrid event on June 17, 1909, and total eclipses from June 29, 1927 through September 9, 2648. The series ends at member 77 as a partial eclipse on April 17, 3009. The longest eclipse will occur on June 25, 2522, with a maximum duration of totality of 7 minutes, 12 seconds. [11]

Metonic series[edit]

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days).


  1. ^ "2017 August 21 Total Solar Eclipse". USNO. Retrieved 25 April 2014. 
  2. ^ Total and Annular Solar Eclipse Paths 19861-2000
  3. ^ Total and Annular Solar Eclipse Paths 1961-1980
  4. ^ "The Great Baja Eclipse", Discover January 1991. p. 90.
  5. ^ "Thousands Go West for a Total Solar Eclipse Tomorrow; Data May Aid Energy Research Partial Eclipse for New York Best Types of Film Image of Sun on Screen", The New York Times February 25, 1979. p. 26.
  6. ^ "Total Eclipse of the Sun Darkens Skies in Northwest; Total Eclipse Casts Two Minutes of Darkness in West Temperature Falls Sharply Learned of Weather Peculiarities Data on Plasma Sought", The New York Times February 27, 1979. p. A1.
  7. ^ "Let There Be Darkness, Please; When Mercury Is at Quadrature, the Social Director Is a Lonely Man For Two Extremely Short Minutes Everyone Gaped Into the Sky", The New York Times, July 30, 1972. p. XX1
  8. ^ Google Earth Gallery for Solar and Lunar Eclipses, Xavier M. Jubier, 2011
  9. ^ Total Solar Eclipse of 1970 Mar 07, Fred Espenak
  10. ^ Littmann, Espenak, Willcox: Totality: Eclipses of the Sun. pp 253ff
  11. ^ Espenak, Fred (Project & Website Manager), Statistics for Solar Eclipses of Saros 145, NASA, updated 2009 September 26.

External links[edit]