July 1916 lunar eclipse


A partial lunar eclipse occurred at the Moon’s ascending node of orbit on Saturday, July 15, 1916, with an umbral magnitude of 0.7944. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A partial lunar eclipse occurs when one part of the Moon is in the Earth's umbra, while the other part is in the Earth's penumbra. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. Occurring only about 3.5 hours after perigee, the Moon's apparent diameter was larger.

Observations

The Ross Sea party was a component of Sir Ernest Shackleton's Imperial Trans-Antarctic Expedition of 1914–17. Five men were stranded not far away from Cape Evans. There was sea ice between them and the relative safety of the hut on Cape Evans. On May 8 two of the men, Aeneas Mackintosh and Victor Hayward, decided to make an attempt to reach the hut. Soon after they set out, a blizzard hit. When the weather cleared up, the remaining men tried to look for them, but realized that the ice was far too thin to cross, and that their friends had been lost. Now they knew that they should wait for a thicker ice and for the full moon to attempt the crossing. Having the full moon was essential, because during polar night the moon is the only source of natural light other than the extremely dim light of the stars.
The weather did not cooperate during the full moon of June, but on July 15, everything seemed to be just right: calm weather, thick ice, clear skies and a full moon. The men started their journey in the morning. When the moon rose, however, the men were surprised to find it was about to be eclipsed. Ernest Wild wrote later:
Although the eclipse continued for a few hours, the men were fortunate because it was only a partial eclipse. They reached Cape Evans later on the same day.

Visibility

The eclipse was completely visible over eastern North America, South America, and Antarctica, seen rising over western North America and the central Pacific Ocean and setting over Africa and western Europe.

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
ParameterValue
Penumbral Magnitude1.73508
Umbral Magnitude0.79437
Gamma−0.59568
Sun Right Ascension07h36m32.1s
Sun Declination+21°35'52.3"
Sun Semi-Diameter15'44.1"
Sun Equatorial Horizontal Parallax08.7"
Moon Right Ascension19h37m12.9s
Moon Declination-22°11'11.4"
Moon Semi-Diameter16'43.6"
Moon Equatorial Horizontal Parallax1°01'23.4"
ΔT18.8 s

Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months 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.
July 15
Ascending node 		July 30
Descending node
Penumbral lunar eclipse
Lunar Saros 118		Annular solar eclipse
Solar Saros 144

Related eclipses

Eclipses in 1916

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 118

Inex

Triad

Lunar eclipses of 1915–1918

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours at alternating nodes of the Moon's orbit.
The penumbral lunar eclipses on March 1, 1915 and August 24, 1915 occur in the previous lunar year eclipse set.

Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days. This lunar eclipse is related to two annular solar eclipses of Solar Saros 125.
July 10, 1907July 20, 1925