But July 31 will mark a rare occurrence for Earth's natural satellite — a phenomenon known as a black Moon. The sparse celestial event will be seen in North America, marking the first occurrence since 2016. The rest of the planet will see the black Moon on Aug. 30.
Although there is no one single definition of a black Moon, according to Time and Date, it is most commonly used to represent the second new Moon of a month. This rarely happens outside of leap years, as lunar cycles largely take 29 days to complete. But every 32 months or so, there are two full Moons in a month, with the first being known as a blue Moon.
Officially, the black Moon will occur at 11:13 p.m. EDT, for the Western Hemisphere according to Space.com. For the Eastern Hemisphere, it will occur after midnight on Aug. 1, but it is not the second new Moon, so it does not count as a black Moon.
New Moons are not able to be seen, as they travel "across the sky with the Sun during the day," according to EarthSky.org. "But the gravitational influence of the new moon and sun combine to physically affect our water planet, which people along the ocean coastlines may notice in the coming days."
Other meanings of a black Moon include a third new Moon in a season of four new Moons; no new Moon in February; and no full Moon in February.
Tomorrow's black Moon will also be a supermoon, which means the new Moon happens at the closest point to Earth in its monthly orbit.