What's a 'super flower blood moon'? What to know about tomorrow's dazzling eclipse

A spectacular lunar event is expected Wednesday as the moon may appear bigger and brighter while radiating a reddish color.

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In the wee hours of the morning Wednesday, astronomers and amateurs alike can look to the sky to witness a so-called "super blood moon."

If that sounds ominous, fret not. The super blood moon, visible to the Western United States, is called that because it combines two lunar phenomena happening at once, according to Michael Shanahan, the planetarium director at the Liberty Science Center in New Jersey.

The "super" part addresses a supermoon event, which takes place when a full moon is slightly closer to the Earth than usual, thus appearing bigger. Supermoons happen a few times a year, but recently they have become popular with sky watchers.

The "blood" aspect comes from a "blood moon," a term for a total lunar eclipse. This is when the Earth blocks the sunshine to the moon, therefore casting a shadow and giving the moon a reddish appearance, as Dylan Dreyer explained on TODAY Tuesday.

Shanahan also offered a bit more of the science behind the eclipse.

"The full moon goes into the dark inner shadow the earth," he told TODAY by email. "However, while our atmosphere blocks the shorter wavelengths such as blue light, it does allow the longer wavelengths of red light to pass through our atmosphere and continue on to the moon, so the moon often turns an eerie copper color during these total lunar eclipses."

The super blood moon may also be referred to as the "flower" supermoon (or "super flower blood moon"), taken from the Farmers' Almanac and named after all the flowers that bloom this time of year. The almanac says its monthly full-moon names originate from Native Americans, though Shanahan said he has not found any original documentation.

The full moon of April, the "pink" supermoon, rises over the skyline of Manhattan on April 26.Angela Weiss / Getty Images

The full moon Wednesday will be the second of 2021's two supermoons, according to the almanac, following a "super pink moon" at the end of April. May’s moon will be a bit closer to Earth compared to the one in April, but only by about 98 miles, NASA says, so it won't appear much bigger or brighter.

The super blood moon will be visible over eastern Asia, the Pacific Ocean and areas west of the Rockies in the U.S. Most of the East Coast will miss it since the moon will be below the horizon at the time of the full eclipse.

“Folks in Hawaii and the Aleutian Islands will get to see the entirety of this eclipse – it will be quite a show for them,” Bill Cooke, who leads NASA's Meteoroid Environments Office, said in a blog post on NASA's website.

Shanahan recommended the website Time and Date for more information about visibility times across the world.

April's "pink" supermoon sets behind the Eiffel Tower in Paris on April 27. It reached peak size in the day's early hours.Sam Tarling / Getty Images

The super pink moon in April drew sky watchers around the globe, with photographers snapping stunning pictures from New York City to Sydney to Stonehenge.