Daily Extra :
young: When used to describe a planetary surface "young" means that the visible features are of relatively recent origin, i.e. that older features have been destroyed (e.g. by erosion or lava flows). Young surfaces exhibit few impact craters and are typically varied and complex. In contrast an "old" surface is one that has changed relatively little over geologic time. The surfaces of Earth and Io are young; the surfaces of Mercury and Callisto are old.
Who Was Born Today?:
1862: Robert Emden, Swiss geo/astro physics, Emden-polytroop
1904: George Gamow, nuclear physicist, cosmologist and writer, 1, 2, 3...ì
1923: Patrick Moore, born in England, astronomer and writer, A-Z of Astronomy
1937: Yuri Aleksandrovich Senkevich, Russian cosmonaut
Who Died Today?:
Today in History:
1959: U.S. Pioneer IV misses Moon and becomes 2nd (U.S. 1st) artificial planet
1968: Orbiting Geophysical Observatory 5 launched
1982: NASA launches Intelsat V
1990: U.S. 65th manned space mission STS 36 (Atlantis 6) returns from space
1994: Space shuttle STS-62 (Columbia 16), launches into orbit
1996: NEAR, USA Asteroid Orbiter (Near Earth Asteroid Rendezvous) imaged Comet Hyakutake.
1997: Comet Hale-Bopp directly above the Sun (1.04 AU)
1997: Zeya Start-1 launched (Russia)