The phrase "nighttime sky" refers to the view of the sky during the night when it is dark outside. It includes stars, the moon, and other celestial objects that are visible when the sun is not out. Full definition
Mirroring a methodology Manning and his colleagues have used to understand other elements of the visitor experience, the researchers showed park visitors a series of photographs of nighttime skies at Acadia with successively more light pollution. (sciencedaily.com)
Four billion years from now, after its first close pass through the Milky Way, a view of Earth's nighttime sky shows that M31 is tidally stretched out and the Milky Way is also warped (Image: NASA / STScI) (newatlas.com)
Not only do the types of stars differ in many ways from what we can see in our serene nighttime sky from Earth, but the stars at the galactic center are also not behaving like the stars around us. (keckobservatory.org)