Mariner 6
Mariner 6 — the first of NASA/JPL's twin 1969 Mars flybys (closest approach 31 July 1969, about 3,430 km up). It returned roughly 75 photographs and showed the thin Martian air is ~98% carbon dioxide and its south polar cap is frozen CO₂ — though its cratered images gave an early, misleadingly Moon-like picture of Mars.
Key facts
Mission & specifications
Mission
- Operator
- NASA / JPL
- Launched
- February 25, 1969
- Status
- Completed
Trajectory
- Distance from the Sun
- 1.51 AU
- Distance from Earth
- 1.89 AU
- Distance from Mars
- 1,815,068 km
Mission
Mariner 6 was the first of a pair of twin spacecraft NASA sent to Mars in 1969, and the first to carry a serious camera system there. Launched on 25 February 1969, it flew past Mars on 31 July at an altitude of about 3,430 kilometres. It returned around seventy-five photographs — dozens taken on approach as the planet grew from a dot into a disc, and a close set snapped during a frantic seventeen-minute pass. Its spectrometers established that the thin Martian atmosphere is roughly 98 percent carbon dioxide, at a surface pressure less than a hundredth of Earth's, and that the bright south polar cap is frozen carbon dioxide rather than water ice. Its images, however, happened to fall on heavily cratered terrain, reinforcing an early and misleading impression of Mars as a dead, Moon-like world — a picture that later orbiters, seeing the volcanoes and canyons Mariner 6 had missed, would overturn.
- 1969First of the twin Mars flybysLaunch
The first of NASA's two 1969 Mars flyby craft launches on an Atlas-Centaur.
- 1969Mars flybyFlyby
Returns ~75 images and shows the thin air is ~98% CO₂ and the south polar cap is frozen carbon dioxide.
- 1971Tracking endsMission end
A heliocentric derelict thereafter; tracking continued into 1970–71 (exact end uncertain).
Images
Images from open archives · credit shown per image