Oklahoma Viewer Captures 96% Lunar Eclipse in Time-Lapse as Clear Skies Reveal Blood Moon

Q: Why did Thursday's Sturgeon Moon turn a mysterious deep crimson instead of completely vanishing into the Earth's shadow?

It turned deep crimson because Earth’s shadow did not make the Moon disappear entirely; instead, sunlight was filtered through Earth’s atmosphere and redirected onto the lunar surface, leaving mostly red and orange light. Thursday’s event was a near-total, not total, lunar eclipse. At maximum, about 96% of the Sturgeon Moon passed through Earth’s dark central shadow, the umbra, but a thin sliver remained in direct sunlight. That is why the Moon did not fully vanish. The red color came from the same physics that makes sunsets look red. As sunlight passes through Earth’s atmosphere, shorter blue wavelengths are scattered away more easily, while longer red and orange wavelengths are bent, or refracted, into Earth’s shadow and onto the Moon. NASA and other astronomy sources describe it as if Earth’s sunrises and sunsets were being projected across the lunar surface. The exact shade can vary. Depending on dust, smoke, volcanic particles and general atmospheric conditions, an eclipsed Moon can look copper, reddish-orange, brownish or even dark gray. In this case, with nearly the whole Moon inside the umbra and only a narrow bright edge left lit, observers saw an especially dramatic deep red glow rather than a complete blackout.

Q: How does an ancient 18-year cosmic cycle dictate the exact moment our moon transforms into a glowing copper sphere?

The “18-year cosmic cycle” is the Saros cycle, and it predicts nearly matching eclipses every 18 years, 11 days and 8 hours. It works because three lunar rhythms line up again almost perfectly: the Moon returns to the same phase, near the same orbital node, and at nearly the same distance from Earth. When those cycles realign, the Sun, Earth and full Moon repeat almost the same geometry, producing another eclipse in the same family. That geometry dictates the exact moment the Moon turns coppery. A lunar eclipse happens only at full Moon, when Earth sits between the Sun and Moon, and only when the Moon is close to one of its orbital nodes, the points where its tilted orbit crosses Earth’s orbital plane. Astronomers can calculate to the second when the Moon enters Earth’s umbra, the dark central shadow, and when maximum eclipse occurs. For the eclipse seen in Oklahoma, NASA places the greatest eclipse at about 11:13 p.m. CDT Thursday, with roughly 96.2% to 96.3% of the Moon’s visible disk inside the umbra. That is why the Moon appeared nearly fully shadowed but not totally eclipsed. The copper-red color is caused not by the Saros itself, but by Earth’s atmosphere. As direct sunlight is blocked, red wavelengths are bent through the atmosphere and onto the Moon, while bluer light is scattered away. This eclipse belongs to Saros 138; the previous one in that series was on Aug. 16, 2008, and the next will come on Sept. 7, 2044.

3 articles · Updated · KOCO Oklahoma City · Aug 28

Aaron Jenison shared a time-lapse from Yukon showing Thursday night’s partial lunar eclipse, with about 96% of the moon passing through Earth’s umbra.
Clear skies across Oklahoma gave viewers an unobstructed look from roughly 9:20 p.m. to nearly 11:30 p.m. as Earth’s shadow turned the moon a reddish-orange “blood moon.”
NASA said the eclipse fell just short of totality; a lunar eclipse occurs when Earth moves between the sun and the moon.
Thursday’s event was Oklahoma’s first lunar eclipse since March, and the state’s next total lunar eclipse is not expected until June 25, 2029.