International Day of Human Space Flight © NASA
Sixty-one years ago today, Yuri Gagarin became the first human to see Earth from space, with a view likely similar to this image of the waning gibbous moon taken from the International Space Station. With a call of "Poyekhali!" ("Off we go!"), Gagarin launched into low Earth orbit in his Vostok 3KA spacecraft, making history in less than two hours with a complete trip around the planet. Landing in rural Russia, he became an instant worldwide celebrity—that is, after convincing puzzled locals he was a comrade and not a space alien.