A total solar eclipse occurred at the Moon's descending node of orbit between Monday, July 29, and Tuesday, July 30, 1878, with a magnitude of 1.0450. 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 kilometres wide. Occurring about 2.4 days before perigee (on August 1, 1878, at 6:45 UTC), the Moon's apparent diameter was larger.
The path of totality was visible from parts of modern-day eastern Russia, Alaska, western Canada, Washington, Idaho, Montana, Wyoming, Colorado, New Mexico, Kansas, Oklahoma, Texas, Louisiana, Cuba, Haiti, and the Dominican Republic. A partial solar eclipse was also visible for parts of Northeast Asia, North America, Central America, the Caribbean, and northern South America.
Newspapers in the United States reported of large migrations from the Midwest towards the path of totality to view the eclipse. Scientists observing from Pikes Peak in Colorado contended with altitude sickness and snowstorms, among other problems.
High-altitude astronomy The 1878 eclipse was a turning point in modern astronomy, because it was the first time that many of the world's leading astronomers had the opportunity to make their observations from the higher altitudes provided by the Rocky Mountains. After the 1878 eclipse, astronomers began to build observatories at locations well above sea level, including on the sides and summits of mountains, a scientific trend which extended throughout the twentieth century and into the twenty-first.
Eclipse images
Étienne Léopold Trouvelot
Eclipse details Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the Moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.
+July 29, 1878 Solar Eclipse Times Event Time (UTC) First Penumbral External Contact 1878 July 29 at 19:18:31.9 UTC First Umbral External Contact 1878 July 29 at 20:23:40.9 UTC First Central Line 1878 July 29 at 20:24:46.4 UTC First Umbral Internal Contact 1878 July 29 at 20:25:52.4 UTC Equatorial Conjunction 1878 July 29 at 21:23:06.4 UTC Ecliptic Conjunction 1878 July 29 at 21:40:46.5 UTC Greatest Duration 1878 July 29 at 21:46:11.9 UTC Greatest Eclipse 1878 July 29 at 21:47:17.7 UTC Last Umbral Internal Contact 1878 July 29 at 23:08:56.0 UTC Last Central Line 1878 July 29 at 23:10:04.0 UTC Last Umbral External Contact 1878 July 29 at 23:11:11.6 UTC Last Penumbral External Contact 1878 July 30 at 00:16:08.9 UTC
+July 29, 1878 Solar Eclipse Parameters Parameter Value Eclipse Magnitude 1.04495 Eclipse Obscuration 1.09192 Gamma 0.62323 Sun Right Ascension 08h35m50.0s Sun Declination +18°38'42.9" Sun Semi-Diameter 15'45.4" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 08h36m44.1s Moon Declination +19°13'31.6" Moon Semi-Diameter 16'15.3" Moon Equatorial Horizontal Parallax 0°59'39.2" ΔT -4.7 s
Eclipse season
This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.
+ Eclipse season of July–August 1878 July 29Descending node (new moon) August 13Ascending node (full moon) Total solar eclipseSolar Saros 124 Partial lunar eclipseLunar Saros 136
Related eclipses Eclipses in 1878 An annular solar eclipse on February 2. A partial lunar eclipse on February 17. A total solar eclipse on July 29. A partial lunar eclipse on August 13.
Metonic Preceded by: Solar eclipse of October 10, 1874 Followed by: Solar eclipse of May 17, 1882
Tzolkinex Preceded by: Solar eclipse of June 18, 1871 Followed by: Solar eclipse of September 8, 1885
Half-Saros Preceded by: Lunar eclipse of July 23, 1869 Followed by: Lunar eclipse of August 3, 1887
Tritos Preceded by: Solar eclipse of August 29, 1867 Followed by: Solar eclipse of June 28, 1889
Solar Saros 124 Preceded by: Solar eclipse of July 18, 1860 Followed by: Solar eclipse of August 9, 1896
Inex Preceded by: Solar eclipse of August 18, 1849 Followed by: Solar eclipse of July 10, 1907
Triad Preceded by: Solar eclipse of September 27, 1791 Followed by: Solar eclipse of May 30, 1965
Solar eclipses of 1877–1880
The partial solar eclipses on March 15, 1877 and September 7, 1877 occur in the previous lunar year eclipse set, and the partial solar eclipse on December 2, 1880 occurs in the next lunar year eclipse set.
Solar eclipse series sets from 1877 to 1880 Descending node Ascending node Saros Map Gamma Saros Map Gamma 114 August 9, 1877Partial 1.3277 119 February 2, 1878Annular −0.9071 124 July 29, 1878Total 0.6232 129 January 22, 1879Annular −0.1824 134 July 19, 1879Annular −0.1439 139 January 11, 1880Total 0.6136 144 July 7, 1880Annular −0.9406 146 December 31, 1880Partial 1.1591
Saros 124
Metonic series
Tritos series
Inex series
References
NASA graphic Googlemap NASA Besselian elements Sketch of Solar Corona July 29, 1878
Further reading
Steve Ruskin (2017). America's First Great Eclipse: How Scientists, Tourists, and the Rocky Mountain Eclipse of 1878 Changed Astronomy Forever. Alpine Alchemy Press. . Steve Ruskin (2008). "'Among the Favored Mortals of Earth': The Press, State Pride, and the Great Eclipse of 1878." Colorado Heritage 28(3), 22–35.
External links
See You on the Dark Side of the Moon (Notre Dame Magazine) The Eclipse That Made America Great (The Atlantic)