Portal:Astronomy/Did you know/5

... that although color-blind, Nicholas U. Mayall was better able to detect faint galaxies than most other astronomers?
... that The Man in the Moone, a 1638 book by the English bishop Francis Godwin, is considered one of the first science fiction books?
... that the galaxy Markarian 501 produces very high energy gamma rays?
... that the Near-Earth object and Mars-crosser asteroid 2007 WD5 is estimated to have a 1-in-75 chance of colliding with Mars?
... that hydroxyl megamasers were used to make the first detection of Zeeman splitting in a galaxy other than the Milky Way?