... For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. ... Fifty years ago (on January 31, 1958) the First Explorer, was launched into Earth orbit by the Army Ballistic Missile Agency. ... Asteroid 2007 TU24 Passes the Earth . ... Mercury on the Horizon . ... Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. ... Crescent Mercury in Color ...