An eclipse 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.[1] Solar eclipse series sets from 2015–2018 Descending node Ascending node Saros Map Gamma Saros Map Gamma 120 Longyearbyen, Svalbard 2015 March 20 Total 0.9453 Solar Dynamics Observatory 2015 September 13 Partial -1.1004 130 Balikpapan, Indonesia 2016 March 9 Total 0.2609 135 L'Étang-Salé, Réunion 2016 September 1 Annular -0.3330 140 Partial from Buenos Aires 2017 February 26 Annular -0.4578 145 Casper, Wyoming 2017 August 21 Total 0.4367 150 Partial from Olivos, Buenos Aires 2018 February 15 Partial -1.2117 155 Partial from Huittinen, Finland 2018 August 11 Partial 1.1476 Partial solar eclipses on July 13, 2018, and January 6, 2019, occur during the next semester series.