The incredible true story of how a team of scientists compiled the first image of Mars one tiny piece at a time

As the very first close-up image of another planet beamed to Earth on July 15, 1965, the engineers at NASA's Jet Propulsion Laboratory couldn't wait to see it.

This was Mariner 4, the first spacecraft to photograph the surface of Mars. At the time, it was the farthest any human-made object had ever traveled.

But the computers were going to take eight hours to process a single image before the excited scientists could get a glimpse.

So engineer Richard Grumm had the idea that they should print out the data as it came in from a tape recorder receiving the signal from the spacecraft — and the engineers colored the first image by hand. Dan Goods, a visual strategist at JPL, retold this incredible story on his blog, Directed Play.

Here's how it happened:

The engineers printed out the series of ticker tape strips of paper with numbers on them indicating how bright each pixel of the first image was going to be, and put them on the wall.

NASA

Goods wrote that Grumm picked up some pastels from a nearby art store, and chose the most perfect color palette imaginable — especially considering the final image was going to arrive in black and white.

"It is uncanny how close his color scheme is to the actual colors of Mars. It's as if they came right out of current images of the planet," Goods wrote. "I've seen some of the other color schemes he tried and it could have been green or purple!"

NASA

The brown bottom of the image is space, while the light area in the middle represents the edge of Mars. The other colors are mostly clouds.

NASA/JPL

NASA hid the engineers and their art project away from the prying media, but word eventually got out, Goods wrote. The paint-by-numbers version ended up being the first Mars image broadcast on TV, instead of the processed photo.

Considering how beautiful the colored-in image is, the real one may have been a bit of a letdown:

"It was an exciting experience to realize that we were actually receiving knowledge from a man-made machine almost 150 million miles away," Robert B. Leighton, who led the Mariner 4 team, wrote in Scientific American the following year. "Of course we were seeing only a sequence of bare numbers. What would the picture look like? Eight hours seemed an eternity to wait."

Source: Scientific American

We've since sent a few more spacecraft to orbit Mars, and landed rovers on its surface. The images we can get of the Red Planet today make the first one look like nothing at all.

But its story captures the excitement that we'll likely feel the first time humans land on Mars — instead of just robots.