A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Tuesday, July 7, 2009,[1] with an umbral magnitude of −0.9116. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into 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 8 hours before apogee (on July 7, 2009, at 17:40 UTC), the Moon's apparent diameter was smaller.[2] This eclipse entered only the southernmost tip of the penumbral shadow and thus was predicted to be very difficult to observe visually.[3]
This eclipse was the second of four lunar eclipses in 2009, with the others occurring on February 9 (penumbral), August 6 (penumbral), and December 31 (partial).
Visibility
The eclipse was completely visible over eastern Australia and western North and South America, seen rising over western Australia and setting over eastern North and South America.[4]
Hourly motion shown right to left
The Moon's hourly motion across the Earth's shadow in the constellation of Sagittarius.
Visibility map
Eclipse details
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[5]
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. The first and last eclipse in this sequence is separated by one synodic month.[6][7][8]
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 (a semester) at alternating nodes of the Moon's orbit.[9]
This eclipse is a part of Saros series 110, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on May 28, 747 AD. It contains partial eclipses from August 23, 891 AD through April 18, 1288; total eclipses from April 29, 1306 through September 5, 1522; and a second set of partial eclipses from September 16, 1540 through April 22, 1883. The series ends at member 72 as a penumbral eclipse on July 18, 2027.
The longest duration of totality was produced by member 38 at 103 minutes, 8 seconds on July 3, 1414. All eclipses in this series occur at the Moon’s ascending node of orbit.[10]
Greatest
First
The greatest eclipse of the series occurred on 1414 Jul 03, lasting 103 minutes, 8 seconds.[11]
Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[12] This lunar eclipse is related to two partial solar eclipses of Solar Saros 117.