Mariner IV was the fourth in a series of spacecraft used for planetary exploration in a flyby mode and the first spacecraft to succesfully image a planet. It was launched on 28 November 1964 by an Atlas/Agena rocket and flew by Mars on July 15, 1965.
The total data returned by the mission was 5.2 million bits including 21 pictures plus 21 lines of a 22nd picture and took more than a week to transmit to earth with the 8.33 bps transmission rate of the spacecraft. The images returned showed a Moon-like cratered terrain (which later Mariner IX showed was not typical for Mars, but only for the more ancient region imaged by Mariner IV). Though not as good looking as images returned by later missions these 22 images are mankind's first images taken by a planetary spacecraft and have great historical value.
This image is Copyright © by A. Tayfun Oner.