The Super Flower Blood Moon occurred on May 15 at 6:32 p.m. PT and reached lunar eclipse totality at 8:29 p.m. (PT), creating the “longest total eclipse in 33 years.”
A lunar eclipse is when the Earth and sun are in a straight line, with this May spectacle being the first total lunar eclipse of 2022.
“Lunar eclipses occur when Earth aligns between the sun and the moon and casts a shadow across the lunar surface,” Space writer Daisy Dobrijevic said.
There are three types of lunar eclipses: total, partial and penumbral. A total lunar eclipse begins with the partial shading of Earth by the penumbra shadow, or penumbral eclipse, followed by the umbra shadow beginning to cover the moon, called a partial eclipse, and completes the third stage with the umbra completely covering the moon in a total eclipse.
Diagram of the lunar eclipse event in which Earth blocks sunlight from the moon, creating a shadow. Photo provided by Space.com.
During the May 15-16 eclipse, observers witnessed the blood moon, in which the moon appeared to be darkened with a reddish hue.
According to UCI physics and astronomy assistant professor Paul Robertson, “it gets that [red] color because the only sunlight reaching [the moon] filters through Earth’s atmosphere … Earth’s atmosphere scatters blue light, allowing only the red light to pass all the way through to the moon.”
A blood moon is different from a supermoon in that each term describes a different aspect of the moon, meaning that the two phenomena can occur simultaneously. A blood moon refers to the appearance of red color during a total lunar eclipse, while a supermoon refers to the distance the moon maintains from Earth.
“A blood moon is just another name for a lunar eclipse, which can only happen when there is a full moon,” Robertson said.
According to NASA, “a supermoon occurs when the Moon’s orbit is closest (perigee) to Earth at the same time the Moon is full.” Perigee, or the closest point of the moon’s elliptical orbit to Earth, is 253,000 miles on average.
The Farmer’s Almanac, which uses data from Fred Espanak who is a retired NASA astrophysicist who specialized in eclipse predictions, declared the Super Flower Blood Moon as the first of four total predicted supermoons in 2022.
To learn more about the day-by-day listing of celestial events, visit the NASA website here.
Natalie Ringdahl is a STEM Intern for the spring 2022 quarter. She can be reached at nringdah@uci.edu.