Fifty years ago today, humanity landed on Mars for the very first time. Viking 1 transformed our view of the Red Planet—and sparked a debate about life beyond Earth that still isn't over. https://t.co/TD0aDVjJHz https://t.co/AZTzkutflm #MarsMission #Viking1 #SpaceExploration #Nospecificcountrycodescanbeidentifiedinthetweet.