Using the Arecibo Radio Telescope in Puerto Rico, a team of radio astronomers led by Gordon Pettengill makes the determination that Mercury rotates on its axis once every 59 Earth days, a much shorter “day” for Mercury than the previously estimated 88 Earth day rotation. Pettengill is a pioneer of radio and radar astronomy, and will go on to use both methods to study asteroids, Venus, and Earth’s moon.
theLogBook.com
https://www.theLogBook.com
Earl Green is the creator, curator, and head writer of theLogBook.com.
Also of interest...
ESSA-8
December 15, 1968
GOES-11 goes weather watching…after a while
May 3, 2000
GOES-12 goes a little haywire
July 23, 2001