Mariner 4 launched toward the first close-up photos of Mars

On November 28, 1964, NASA launched Mariner 4 toward Mars. Roughly eight months and millions of miles later, on July 14, 1965, it swept past the planet at about 6,100 miles, becoming the first spacecraft to fly by Mars and return close-up images of another world.

The encounter lasted only about 25 minutes of observation. Its slow-scan camera captured 21 full pictures, painstakingly beamed back to Earth in the days that followed at a trickle of bits per second.

The grainy, gray frames revealed a cratered, Moon-like surface — no canals, no cities, no obvious water.

Those images quietly retired centuries of speculation about Martian civilizations and reframed the planet as a cold, barren world. The little probe far outlived its planned mission, surviving about three years in solar orbit while studying the solar wind, and it opened the modern age of Red Planet exploration.