Skywatchers are in for a treat on Monday morning as the full Worm Moon will be partially eclipsed by Earth's shadow, creating a subtle penumbral lunar eclipse.
The moon, reaching peak fullness at 3:00 AM ET, will be adorned with the traditional name "Worm Moon" according to the Farmers' Almanac, reflecting the emergence of earthworms and other creatures from winter slumber.
A few hours earlier, at 12:53 AM ET, the celestial event begins. The Earth, Moon, and Sun will align near-perfectly, causing the Earth's outer shadow, called the penumbra, to fall upon the moon's surface.
A Subtle Shift in Light
The peak of the eclipse occurs at 3:12 AM ET, when the moon may appear slightly dimmer than usual, explains Dr. Shannon Schmoll, director of the Abrams Planetarium at Michigan State University. "It'll be a gradual darkening from one side of the moon to the other," she says, "not a dramatic change."