July 2018 lunar eclipse


A total lunar eclipse occurred at the Moon’s descending node of orbit on Friday, July 27, 2018, with an umbral magnitude of 1.6100. It was a central lunar eclipse, in which part of the Moon passed through the center of the Earth's shadow. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. 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. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 19 hours after apogee, the Moon's apparent diameter was smaller.
This was the first central lunar eclipse since June 15, 2011. It was also the longest total lunar eclipse of the 21st century, but not the longest in the 3rd millennium. Totality lasted one hour and 42.955 minutes, a period "just short of the theoretical limit of a lunar eclipse ". The Moon remained at least partially in Earth's shadow for three hours 54.55 minutes. The longest total lunar eclipse of the 3rd millennium will occur on May 12, 2264, lasting 106 minutes and 13.2 seconds, which will be the longest total lunar eclipse since 2000, and the longest one until 3107.
The eclipse occurred when the Moon was near its maximum distance from Earth, which caused the Moon to appear smaller than normal, and to travel at its slowest speed in its orbit around Earth.
This lunar eclipse coincided with Mars being nearly as close as possible to Earth, a concurrence that happens once every 25,000 years.

Background

A lunar eclipse occurs when the Moon passes within Earth's umbra. As the eclipse begins, Earth's shadow first darkens the Moon slightly. Then, the Earth's shadow begins to cover part of the Moon, typically turning it a dark red-brown color. The Moon appears to be reddish because of Rayleigh scattering and the refraction of that light by Earth's atmosphere into its umbra.
The Moon's brightness is exaggerated within the umbral shadow. The southern portion of the Moon was closest to the center of the shadow, making it the darkest, and most red in appearance.

Visibility

The eclipse was completely visible over east Africa, southern Africa, south and central Asia, seen rising over South America, west Africa, and Europe, and setting over east Asia and Australia.

Visibility map

Eclipse details

Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.
ParameterValue
Penumbral Magnitude2.68050
Umbral Magnitude1.60996
Gamma0.11681
Sun Right Ascension08h28m22.0s
Sun Declination+19°04'25.2"
Sun Semi-Diameter15'45.0"
Sun Equatorial Horizontal Parallax08.7"
Moon Right Ascension20h28m18.2s
Moon Declination-18°58'10.6"
Moon Semi-Diameter14'42.7"
Moon Equatorial Horizontal Parallax0°53'59.7"
ΔT68.9 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. The first and last eclipse in this sequence is separated by one synodic month.
July 13
Ascending node
July 27
Descending node
August 11
Ascending node
Partial solar eclipse
Solar Saros 117		Total lunar eclipse
Lunar Saros 129		Partial solar eclipse
Solar Saros 155

Related eclipses

Eclipses in 2018

Metonic

Tzolkinex

Half-Saros

Tritos

Lunar Saros 129

Inex

Triad

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 total solar eclipses of Solar Saros 136.
July 22, 2009August 22, 2027