#OTD December 31, 1999 Ellie Arroway became the first human to make Contact with an extraterrestrial intelligence. She traveled aboard "The Machine" whose plans were received while she searched for signs of intelligent life by listening to radio static from space for "Patterns in the Chaos" #SciFi

#OTD 50 years ago, the Altair 8800 microcomputer kit went on sale. It was the first commercially successful personal computer and began the 1970s computer revolution. It had no video output and was programed via switches or terminal, later using Micro-soft's first product, Altair BASIC #histtech

#OTD Dec 14, 1972 the last humans on the moon left the lunar surface to return to the earth aboard Apollo 17. No one has yet returned.

#OTD Dec 6, 1882 The transit of Venus across the sun was photographed on a series of glass plates by David Peck Todd using a solar telescope on the summit of Mount Hamilton. Venus transits were predicted by Johannes Kepler in 1627 and occur in eight-year pairs with gaps of 100+ years between pairs.