A Moon to Remember

The May 26 lunar eclipse as seen from the Foothill Observatory in Los Altos Hills, California

In the early morning hours of May 26, stargazers in Santa Cruz who had set their alarms got to witness a unique event: a lunar eclipse. The “super flower blood moon” lunar eclipse was visible under clear skies in western North and South America, eastern Asia and Australia, New Zealand, and islands in the South Pacific Ocean.

“It always makes me feel more connected to nature when I take time to look at the moon and the stars,” said local astronomy enthusiast Lindsay Roberts. “It gets me and my kids away from the TV and gets us focused on the beauty that surrounds us.” 

The Earth’s shadow started to cover the moon at 1:46 a.m. (PDT), with the total lunar eclipse occurring at 4:11 a.m. The total eclipse lasted about 14 minutes. What made this event so unique was the presence of four elements: a lunar eclipse, a supermoon, a full flower moon, and a blood moon. 

It’s extremely rare for all four of these events to occur at the same time. Such a phenomenon will likely not happen again for another 180 years. 

“During a lunar eclipse, the moon, Earth, and sun line up exactly so that the moon passes through the Earth’s shadow,” Dr. Geoff Mathews, an astronomy professor at Foothill College, explained. “A lunar eclipse can only happen during a full moon. That’s when the moon is on the opposite side of the Earth from the sun.” On average, there are two lunar eclipses per year.

A RARE OCCURRENCE

The moon’s orbit around the Earth is like a slightly stretched circle. When it’s at its closest, the moon can appear to be about 10% larger. 

“When a full moon happens at the same time that the moon is at its closest,” Matthews said, “people refer to that as a supermoon.” 

There are typically three to four supermoons per year. But it will be another 12 years before a supermoon coincides with a total lunar eclipse.

The term “flower moon” originated centuries ago. It refers to the flowers of the spring season. When a full moon occurs in May, it’s called a “full flower moon.” This happens only once a year.

WHAT IS A BLOOD MOON?

When the moon is in a total lunar eclipse, it’s called a blood moon. It turns a reddish brown color only during a full lunar eclipse. 

“This is my favorite part of a lunar eclipse, because it’s my chance to see every sunrise and sunset on Earth at the same time,” Mathews said. 

The reason this happens starts with the fact that there is a thin layer of atmosphere around the Earth that lets some sunlight through. Although sunlight includes every color of the rainbow, it does not let all colors in equally. The light gets bounced to the side, which is called scattering. This affects violet and blues the most, and green, yellow, orange, and red the least.

”In the end,” Matthews added, “only the red light makes it through to shine on the moon and get reflected back to our eyes.”