Is your computer taking too long to process data? Spare a thought for the team at NASA's Jet Propulsion Laboratory back in 1965, waiting for their computers to process the first closeup images of Mars taken by Mariner 4. Their solution - colour by numbers! #tbt #AstronoMay (1/9) 
On July 15 1965, Mariner 4 obtained the first closeup images of Mars and stored them in its onboard tape recorder. Over the course of three weeks, the data acquired during the flyby was transmitted back to the Earth. #AstronoMay #MuseumFromHome #sciencefromhome (2/9)
At JPL, a "real-time data translator" machine converted the image data into numbers which were printed onto strips of paper. The team knew the computers would take some time to process the images and they were anxious to see them. Then, they had an idea... #AstronoMay (3/9)
...process the strips by hand! After a quick trip to an art store, where they couldn't get the chalk they wanted and ended up with coloured pastels instead, they assigned colours to the numbers on the strips... #AstronoMay (4/9)
Strip by strip, the image started to build up! #AstronoMay (6/9)
Until finally - the first closeup image of Mars was complete! The image was framed and presented to JPL director William H. Pickering. Curious about how this compares to the actual image? #AstronoMay (7/9)
Here is the computer processed image of Mars taken by Mariner 4. It shows the edge of the planet and the hazy bit just above the edge is thought to be clouds. The black part is empty space! #AstronoMay (8/9)
Want to learn a bit more about Mars? Head here: rmg.co.uk/discover/explo…. And join us for more from the Royal Observatory Greenwich during #AstronoMay! #MuseumFromHome #sciencefromhome (9/9)
