OTD…Oct. 15 and Cassini

Saturn’s clouds have roots deeper inside the planet’s atmosphere than scientists previously thought, and Saturn’s rings — now believed to have formed in the last 200 million years — appear to be raining organic molecules down on the planet, according to observations made by NASA’s Cassini spacecraft last year in the final weeks of its mission.

Today marks the 40th anniversary — July 20, 1976 — of the first U.S. robotic landing on another planet by the Viking 1 spacecraft on Mars.

Apollo 16 launched to the Descartes Highlands of the moon on this day in 1972 with John Young, Charlie Duke and Ken Mattingly.