NASA’s Ingenuity helicopter became the first helicopter to fly on another planet.
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The Treaty of Frankfurt was signed between Holy Roman Emperor Charles V and Protestants.
Grace Kelly married Rainier III, the Prince of Monaco.
Johnny Cash released his 'Ring of Fire' single.
Cardinal Joseph Ratzinger was elected as Pope under the name Pope Benedict XVI.
NetherRealm's Mortal Kombat, the first game in the franchise reboot, was released for PS3 and Xbox 360.