Daily Extra :
Astronomy & Space Word of The Day
stellar classification: Stars designed with a letter & number according to the nature of their spectral lines. The classes are: O, B, A, F, G, K, & M; O stars are the hottest; M the coolest. The numbers are simply subdivisions of the major classes. The classes are oddly sequenced because they were assigned long ago before we understood their relationship to temperature. O & B stars are rare but very bright; M stars are numerous but dim. The Sun is designated G2.
Today in History:
1601: Tycho Brahe died in Prague, Bohemia (now Czech Republic).
1962: Mars 1962A - USSR Mars Flyby launched. Spacecraft failed to leave Earth orbit after the final rocket stage exploded.
1998: Deep Space 1 (DS1) - USA Asteroid and Comet Flyby launched. The Deep Space 1 (DS1) is the first of a series of technology demonstration probes being developed by NASA's New Millennium Program. The spacecraft flew by the Mars-crossing near-Earth asteroid 9969 Braille in July, 1999 and will fly by comet Borrelly in September 2001.
