Along with its twin Mariner 7 spacecraft, Mariner 6 was designed to make a close flyby of Mars to study the surface for signs of life and develop technology for future missions. It took 24 near-encounter photos showing a chaotic and heavily cratered surface as well as the dark features long seen from Earth.

The Mariner 6 spacecraft also had the objective of providing experience and data for the Mariner 7 encounter five days later.

Scientific Instrument(s)

- Imaging system
- Infrared spectrometer
- Infrared radiometer
- Ultraviolet spectrometer
- Conical radiometer