The Milky Way[a] is the galaxy that contains our Solar System, with the name describing the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος (galaxías kýklos, “milky circle”). From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from its outer rim. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies.
A Lunar Eclipse is when our blue/green globe saunters between the trusty moon and glowing sun, our planet completely blocks the luminous rays of the sun but the moon remains visible.
The twin spacecraft flew in an almost-circular orbit until the mission ended on December 17, 2012, when the probes were intentionally sent down to the lunar surface. NASA ultimately named the impact site in honor of the late astronaut Sally K. Ride, who was America's first woman in space and a member of the GRAIL mission team.
Earlier theories suggested that the craggy outline of a region of the lunar surface, named Oceanus Procellarum--or the Ocean of Storms--had resulted from a large asteroid impact. If this theory had been correct, the basin it had dug out would represent the largest asteroid impact basin scarring the lunar surface. However, mission scientists, scrutinizing GRAIL data, now believe that they have discovered new evidence that the craggy outline of this rectangular region--approximately 1,600 miles across--was actually caused by the formation of ancient rift valleys.