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A stone’s throw from High Bay 1, where many of NASA’s pioneering robotic missions are gathered, the first image of Mars ever seen on television was broadcast in 1965.
The groundbreaking image is part of a small exhibit tucked away in a corner of the second floor of the Spacecraft Assembly Facility on the campus of NASA’s Jet Propulsion Laboratory in Pasadena.
But the image, which represented the first picture of another planet taken from space, is not a picture at all.
Instead, it’s a “color by number” representation of data captured by NASA’s Mariner 4 spacecraft on July 15, 1965, and sent to Earth as the probe made its closest approach to Mars.
Mariner 4’s historic encounter with Mars was just the beginning of a series of missions that changed the way we see our planetary neighbors. While the actual photo was also released, the hand-colored image continues to captivate anyone who sees it on JPL.
“The first time I came across this was almost right when I started working here at JPL, which was 17 years ago,” says David Delgado, cultural strategist at The Studio at JPL. “It’s just this object of curiosity and wonder. You can’t just walk past it. The story is so powerful.”
The first to visit other planets
In 1962, Mariner 2 became the first spacecraft to visit another planet when it flew past Venus. The milestone encouraged NASA engineers to move forward with an even more ambitious project: taking pictures of planets from space.
There was a lot of driving on the Mariner 4 mission. It was one of a pair of spacecraft designed to take images of Mars, and the first failed.
Mariner 3 launched on November 5, 1964, but lost power just eight hours later when the payload shroud was not jettisoned and the solar arrays never deployed. With a quickly redesigned shroud, Mariner 4 launched three weeks later, on November 28, before embarking on a 228-day journey to reach Mars.
A television camera was attached to the spacecraft to show what the planet looked like up close from a spacecraft, along with six scientific instruments to study Mars’ surface and atmosphere.
Interest in getting images of other planets from space was part of the space race of the 1960s for a reason. The best map of Mars at the time dates back to the late 1800s and comes from observations made by Percival Lowell using his private Lowell Observatory in Flagstaff, Arizona. And the highest resolution image was captured in 1956 by a telescope on Earth.
Mariner 4 flew 6,118 miles (9,845.5 kilometers) above the surface of Mars on the night of July 14, taking 22 images of the planet.
The spacecraft carried the first digital imaging system used beyond Earth. The machine converted the camera’s analog signal into a digital format and slowly sent the data back to Earth at a rate of 8 1/3 bits per second. The bit rate meant it took 10 hours to send a single image back to Earth.
The transmission was incredibly slow by today’s standards, given that the Perseverance rover regularly sends back batches of high-resolution images of Mars.
Meanwhile, members of the press had gathered at JPL and eagerly awaited the release of the first photo.
As fears mounted, some members of the Mariner 4 team decided to take matters into their own hands.
An unexpected art project
The tape recorder that records data aboard the Mariner 4 was never intended to be used. The equipment was a spare, but because the Mariner 3 never reached Mars, all hopes were on the Mariner 4’s instruments to work. There was a chance that the tape recorder would not work properly.
During the long wait for the first images, Richard Grumm, who oversaw the tape recorder’s operations, and members of his team beg
an converting Mariner 4’s digital data into ones and zeros on ticker tape, according to a project compiled about the image. by Dan Goods, visual strategist at The Studio at JPL.
The team adhered 3-inch-wide strips to a movable wall and decided to literally color by number based on the brightness of each pixel. The team saw these efforts as a way to validate whether the tape recorder worked and captured light reflected from the planet.
Grumm ran to a local art store looking for chalk. His idea was to use different shades of gray, but the store only had a set of colored pastels.
He and his team created a color touch using brown, red, and yellow pastels, and while the choice seems intentional because the colors reflect the actual color palette of Mars, Grumm only thought about what would best mimic a white-to-black gradient.
“There’s a lot of serendipity in this image,” Delgado said of the surprisingly accurate colors.
As the team colored in the numbers, the edge of the planet emerged. Dark brown was used to represent the emptiness of space. The lightest colors represented Mars, and orange depicted clouds in the Martian atmosphere. Dark registration marks from the camera lens also appeared.
Not only did the camera work and take pictures, but the data was good too.
“People were just really scared that this mission wouldn’t work,” Delgado said. “This image we’re seeing here is the result of engineers really trying to validate their hardware to make sure it worked properly.”
Despite the best efforts of JPL’s communications team, journalists got a glimpse of the “color by number” image before the actual photo was released, and the artwork became the first image of Mars from space to be seen on TV.
Later, the piece of wall covered in colored ticker tape was cut out, framed, and donated to JPL director William Pickering.
All 22 images were returned by Mariner 4 between July 15 and August 3, 1965. Together, they revealed craters on the surface of Mars and clouds hovering above the atmosphere, which surprised both scientists. Mariner 4 happened to pass over some of the oldest terrain on Mars, which more closely resembled the heavily cratered surface of the moon.
The snapshots showed less than 1% of the surface of Mars and lacked the more diverse features on the planet’s surface that later missions like Viking 1 would capture.
Mariner 4’s first documentation of Mars sparked a desire to better understand the red planet, which continues to this day as the Perseverance and Curiosity rovers, Ingenuity helicopter and a fleet of orbiters work to unlock more Mars secrets .
“The ability to see something for the first time changes the way I think we think about ourselves,” Delgado said. “The process of being able to connect is to understand what’s out there, and it also feels like the process of understanding who we are within the context of it all.”
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