A "blood moon" was once a terrifying event for our ancestors, who struggled to explain the orb's sudden transformation into a fiery red ball. Modern-day observers understand the science behind the event, but it still provides an opportunity for people to gaze in wonder at the night sky.
On Tuesday night and Wednesday morning, depending on where in the world you were, a total eclipse made a "blood moon" visible for observers in Asia, Australia and North and South America.
"These kinds of events scared the hair off" of our ancestors, who thought the moon was wounded, on fire, or being eaten by a dragon, Alan MacRobert, senior editor of Sky & Telescope Magazine, tells Newsweek. "To see this happening to the moon could really throw you for a loop."
A lunar eclipse occurs when a full moon is directly opposite the sun with the Earth in the middle, MacRobert explains. In other words the moon, Earth and sun must be perfectly aligned. Lunar eclipses occur at most three times a year, according to Fred Espenak, a scientist emeritus at NASA's Goddard Space Flight Center. The Earth's shadow blocks the light from the sun that normally reflects off the moon, enveloping the moon in a bright orange glow.
The eclipse occurs in stages, MacRobert tells Newsweek. First, a bright white full moon begins to enter the Earth's outer shadow, called the penumbra, creating a barely visible shading on one side of the moon. A partial eclipse begins when the moon enters Earth's central shadow, or the umbra.
"It looks like a dark bite is being taken out of that side," says MacRobert. As the moon moves further into the umbra, the edge of the shadow appears to be curved, which MacRobert says is one way the ancient Greeks surmised that the Earth must be round.
The third phase—the total eclipse—occurs when the moon has fully entered the Earth's central shadow, directly opposite the sun, according to Sky & Telescope Magazine. "All of the sunrises and sunsets around the world at the time" fill the Earth's atmosphere and give the moon an orange or red color, MacRobert explains.
"To me it gives the moon a really three-dimensional appearance," MacRobert says. "It sort of looks like a luminous rotten orange."
Mid-Eclipse here in the lower part of New Zealand #LunarEclipse #BloodMoon pic.twitter.com/yTja970JwM
— Paul Stewart (@astrostew) October 8, 2014
Red moon rising between ocean and cloud - all we may get to see of the #lunareclipse tonight... #eclipse pic.twitter.com/uiONeMjaDL
— StangOrton (@StanGorton) October 8, 2014
Lunar eclipse witnessed from Kolkata pic.twitter.com/mrSn2EYLcG
— ANI (@ANI) October 8, 2014
Clear skies made for good lunar eclipse. Here's moon near totality at 6:45 a.m. in Mount Pleasant. #mtpsc #chswx pic.twitter.com/JHWJ2TWk64
— Andrew Knapp (@offlede) October 8, 2014
After roughly an hour of "totality," the moon began moving through the penumbra and out of the Earth's shadow, going through the same stages in reverse, according to Sky & Telescope Magazine.
For those on the East Coast of the U.S., the moon began to set and the dawn sky to grow brighter Wednesday while the total eclipse—which lasted from about 6:25 a.m. until 7:24 a.m. EDT—was still in progress, MacRobert tells Newsweek, whereas observers on the West Coast had a chance to see the entire process in the wee hours of the morning. Unfortunately, clouds over parts of the East Coast made it more difficult for some to see the phenomenon, The New York Times reported.
Wednesday's event was the second and final total eclipse of the moon to occur in 2014; the first took place on April 14 and 15. Two total eclipses will occur in 2015, on April 4 and September 27 and 28, according to Sky & Telescope Magazine.
