Two weeks after a total solar eclipse that missed most of the Western Hemisphere, the Americas — and Chicago — can get in on some of the action Thursday night.
While it won’t be a total eclipse, it is considered a “deep” partial eclipse, with Earth’s shadow covering up to 96.3% of the moon’s area as the celestial satellite passes between the planet and the sun, according to NASA.
During a lunar eclipse, the moon appears red or orange — hence the name “Blood Moon” — as sunlight that Earth doesn’t block filters through its atmosphere on its way to the lunar surface. Blue light scatters easily, while reddish light travels farther, “as if all the world’s sunrises and sunsets are projected onto the Moon,” NASA explains.
From Chicago, the partial eclipse will be visible beginning Thursday at 9:33 p.m., according to the Adler Planetarium. At this time, Earth’s shadow will appear to take an increasingly large bite out of the full moon, NASA scientists say. Native American tribes dubbed the August full moon “Sturgeon Moon” after the large fish from the Great Lakes and Lake Champlain that was caught this time of year.
From Chicago, viewers should face south-southeast, about a third of the way up from the horizon, to see the lunar eclipse Thursday night.
The eclipse will peak — or reach maximum coverage — at 11:13 p.m. The part of the moon still reached by sunlight will be small enough for observers to see as the rest of it takes on a copper color under the Earth’s shadow. The show will end right before 1 a.m. Friday.
Between 10 p.m. Thursday and 1 a.m. Friday, about 25% of skies above the Chicago area will have clouds, according to a National Weather Service forecast. This should allow for prime viewing.
This event is happening soon after the total solar eclipse on Aug. 12 because solar and lunar eclipses always occur about two weeks apart. This is because solar eclipses can only happen during a new moon, and lunar eclipses during a full moon, as the Earth, moon and sun line up.
But eclipses don’t happen every month, even as lunar phases come and go, because the moon orbits Earth on a tilted path, meaning new moons pass slightly above or below the sun from Earth’s point of view, and most full moons pass above or below Earth’s shadow, according to NASA.