Over the next two years, the North Coast sky will host a four-part series of total lunar eclipses -- sometimes called a “Blood Moon” -- starting on the evening of April 14.
Though lunar eclipses are quite common, Astronomers of Humboldt member Jeff Schmitt said this tetrad of eclipses is “kind of exciting.”
”When you end up with several in a row like this, it's sort of unusual,” Schmitt said.
The first lunar eclipse in the tetrad will start at around 10 a.m. on April 14 for the West Coast, with a total phase occurring from around midnight to 1:30 p.m. on April 15.
Tetrads can be rare or common depending the time period, according to Astronomers of Humboldt Vice President Ken Yanosko.
”It kind of goes through cycles,” he said. “There are supposed to be eight or nine tetrads occurring this century, between now and 2100.”
According to the NASA website, several centuries can go by without any tetrads occurring, which was the case from 1600 to 1900.
A total lunar eclipse occurs when the moon is entirely covered by the shadow of the Earth. Rather than being completely darkened by the shadow, Yanosko said, the moon glows an amber red due to sunlight that is refracted from the Earth's atmosphere.
”When sunlight goes through the atmosphere at a large angle, like what we see during a sunset, the sky turns red,” he said. “The moon is just getting the red part of the sunlight, while the blue light gets scattered.”
Yanosko said if a person were to stand on the moon and look at the Earth during the eclipse, there would a “red halo” around the planet.
”That would be the Earth's atmosphere,” he said.
Yanosko said it is just orbits that cause the eclipses, not omens.
”I got an email from some crackpot saying that this was going to be the end of the world,” he said. “There are a lot of rumors and chatter.”
The next three total lunar eclipses will take place on Oct. 8, April 4, 2015, and Sept. 28, 2015.