
StarTalk @StarTalkRadio
#OTD 3/29/1974: Mariner 10 flew past #Mercury, taking the 1st close-ups of the messenger planet. It got to Mercury with the use of a gravitational assist from Venus, the 1st time a spacecraft utilized this important technique: https://t.co/oMn3rs7aLh https://t.co/bV2JZDhKfP — PolitiTweet.org