On this date in 1930, Clyde Tombaugh, searching for a 9th planet, discovered Pluto. This opened the door to further exploration of the outer solar system.
Circumpolar stars are those that never rise nor set from a certain location. At the poles, all stars are circumpolar, while at the equator, no star is.
Astronomers analyzed Gaia data to create an atlas of Milky Way mergers with smaller galaxies, using data about stellar streams and globular clusters as well.
New research shows that a patch of cold water in the North Atlantic Ocean called the “Blue Blob" has temporarily slowed the melting of Iceland’s glaciers.