An orange hue envelops the Earth, known as 'airglow,' a phenomenon that occurs when ultraviolet radiation hits molecules in the atmosphere and creates a band of light that reaches 50 to 400 miles high. More of our top space pictures this year: reut.rs/2KELNFH 
A view of the Cat's Paw Nebula, a star-forming region in the Milky Way galaxy, so named because it resembles a feline footprint, and more of our top photos from space this year: reut.rs/2KELNFH
An exoplanet orbits around the Sun-like star HD 85512 in this NASA artist's impression, and more of our top photos from space this year: reut.rs/2KELNFH
The Betsiboka Estuary in Madagascar, draining into the sea and showing changing landscapes due to decimation of rainforests and coastal mangroves, is seen from the International Space Station. More top photos from space in 2018: reut.rs/2KELNFH
Ultraviolet radiation and stellar winds from a giant star called Herschel 36 push through dust in curtain-like sheets in the Lagoon Nebula stellar nursery, located 4,000 light years away. More of our top photos from space this year: reut.rs/2KELNFH
A computer model of the Sun's magnetic field is shown in this rendering from NASA's Solar Dynamics Observatory. More of our top photos from space in 2018: reut.rs/2KELNFH
