The first image ever transmitted to Earth from another planet was rendered by hand in pastels. On July 14, 1965, the Mars Mariner 4 spacecraft took 22 photographs with its onboard television camera as it made the closest approach of its flyby. The images came down pixel by pixel at the glacial pace of 8 1/3 bits per second. It took over six hours to transmit each photograph, which first emerged as a string of numbers on strips of paper from a teletype machine at Jet Propulsion Laboratory in Pasadena. It took even longer for the computers to process the raw data as a configured television image.
The engineers at JPL, who were worried that there might be a problem with the onboard tape backup system, didnāt want to wait that long to get their first glimpse of the images. So they stapled the teletype strips to the wall in the correct vertical array, went out and bought a box of pastels, assigned colors to each numerical range of value, and took turns making a paint-by-numbers drawing from the first image transmission.
What even is a digital image!?