This Day in American History: Mariner 4 Sends Back Humanity's First Close-Up Photos of Another Planet (July 15, 1965)
- ForAmerica
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This Day in American History: July 15, 1965
For as long as people had pointed telescopes at the night sky, Mars had been a fuzzy orange smudge, close enough to obsess over and far too distant to ever really see. That changed just after midnight on this day in 1965, when NASA's Mariner 4 spacecraft, having survived an eight-month, 325-million-mile journey, swept within 6,118 miles of the Red Planet and became the first human-made object to photograph another world up close.
It almost didn't happen at all. Mariner 4's twin, Mariner 3, had launched three weeks earlier and died in orbit when its protective shroud failed to separate. Engineers scrambled to redesign it, and Mariner 4 slipped off the launch pad just two days before its window closed. Once it reached Mars, its onboard camera fired for barely 25 minutes, capturing 22 images before the spacecraft passed behind the planet and out of contact with Earth.
The wait for the pictures was almost unbearable. Each photo took roughly eight hours just to reach Earth, one excruciatingly slow byte at a time, and then hours more to process. A group of engineers at JPL got so impatient waiting for the computer to finish that they printed out the raw numerical data on paper strips and hand-colored each one like a paint-by-numbers kit, based on what the numbers said the shading should be. Their homemade picture, framed and hung in JPL's hallway, beat the official version to the public eye and became the first image of another planet most Americans ever saw.
NASA's own 1965 documentary on the mission, filmed as the pictures were still coming in.
What the real pictures showed surprised almost everyone: not canals, not vegetation, not the faint hints of alien life some scientists still held out hope for, but a cratered, moon-like wasteland that looked essentially dead. Two weeks later, President Lyndon Johnson personally handed out medals at the White House, calling the achievement "awe-inspiring" in the middle of the Space Race with the Soviets. Mariner 4 kept transmitting data for two more years before finally running out of gas for its attitude thrusters in December 1967, having already answered a question humans had been asking since Galileo first pointed a telescope at Mars in 1610.
Sixty years later, American rovers are still driving across the ground Mariner 4 first photographed from 6,000 miles up. Come back tomorrow for what else happened on July 16 throughout American history.
Also on this day
1853: America's first World's Fair, the Exhibition of the Industry of All Nations, opened at New York's Crystal Palace.
1903: The newly formed Ford Motor Company took its first order, an $850 Model A bound for a Chicago dentist.
1975: The Apollo-Soyuz Test Project launched, a joint U.S.-Soviet mission that would dock American and Russian spacecraft in orbit two days later.
1988: The action classic "Die Hard" hit theaters, launching Bruce Willis to stardom.
1997: Fashion designer Gianni Versace was murdered outside his Miami Beach home.
2006: Twitter publicly launched, eventually growing into a platform with hundreds of millions of users.
Sources: NASA and NASA Science