Mariner 6

NASA

Agency

NASA

Country

🇺🇸 USA

Launched

1969-02-24

Flyby date

1969-07-31

Closest approach

3,431 km

Mass

413.1 kg

Key Findings

1.Returned 75 near-encounter images at markedly improved quality over Mariner 4
2.Measured surface temperatures in the range −73°C to +17°C (varying strongly with latitude and time of day)
3.Detected CO2 in polar cap composition from infrared spectroscopy
4.Revealed diverse terrain types including chaotic terrain and flat, featureless plains
5.Atmospheric surface pressure confirmed at ~6 mbar via radio occultation

Mission Outcome

Mariner 6 was the first of a coordinated dual-spacecraft reconnaissance of Mars in 1969, flying over the equatorial and southern hemisphere regions. Its improved imaging and infrared spectrometry provided the first systematic temperature measurements and revealed terrain diversity beyond the cratered plains seen by Mariner 4. Combined data from Mariner 6 and 7 significantly advanced understanding of Martian atmospheric composition and surface diversity.