July 1973 lunar eclipse
A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Sunday, July 15, 1973, with an umbral magnitude of −0.9581. 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 about 3 days after apogee, the Moon's apparent diameter was smaller.
This eclipse was the third of four lunar eclipses in 1973, with the others occurring on January 18, June 15, and December 10.
This was the first lunar eclipse of Saros series 148.
Visibility
The eclipse was completely visible over Australia, western North America, and Antarctica, seen rising over east Asia and setting over central North America and western South America.Eclipse details
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.| Parameter | Value |
| Penumbral Magnitude | 0.10468 |
| Umbral Magnitude | −0.95805 |
| Gamma | 1.51782 |
| Sun Right Ascension | 07h38m36.3s |
| Sun Declination | +21°30'35.7" |
| Sun Semi-Diameter | 15'44.1" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 19h37m04.9s |
| Moon Declination | -20°10'55.9" |
| Moon Semi-Diameter | 14'48.4" |
| Moon Equatorial Horizontal Parallax | 0°54'20.5" |
| ΔT | 43.9 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.| June 15 Ascending node | June 30 Descending node | July 15 Ascending node |
| Penumbral lunar eclipse Lunar Saros 110 | Total solar eclipse Solar Saros 136 | Penumbral lunar eclipse Lunar Saros 148 |
Related eclipses
Eclipses in 1973
- An annular solar eclipse on January 4.
- A penumbral lunar eclipse on January 18.
- A penumbral lunar eclipse on June 15.
- A total solar eclipse on June 30.A penumbral lunar eclipse on July 15.
- A partial lunar eclipse on December 10.
- An annular solar eclipse on December 24.
Metonic
- Preceded by: Lunar eclipse of September 25, 1969
Tzolkinex
- Followed by: Lunar eclipse of August 26, 1980
Half-Saros
- Preceded by: Solar eclipse of July 9, 1964
- Followed by: Solar eclipse of July 20, 1982
Tritos
- Preceded by: Lunar eclipse of August 15, 1962
- Followed by: Lunar eclipse of June 13, 1984
Lunar Saros 148
- Followed by: Lunar eclipse of July 26, 1991
Inex
- Preceded by: Lunar eclipse of August 4, 1944
- Followed by: Lunar eclipse of June 24, 2002
Triad
- Preceded by: Lunar eclipse of September 13, 1886
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 partial solar eclipses of Solar Saros 155.| July 9, 1964 | July 20, 1982 |