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Mariner 10 · S-band 42 km
~42 km
Measured
5 February 1974. Mariner 10 radio occultation of Venus. S-band penetrated to about 42 km altitude. X-band was lost near 50 km.
Mariner 10’s S-band signal reached about 42 km in Venus’s atmosphere before absorption extinguished it. The X-band died higher, near 50 km.
Documentary plate
NASA / JPL. Magellan global mosaic of Venus. The 42 km is the radio extinction, not the globe.
What it supports
A published radio-occultation extinction altitude. Kliore et al., NTRS 19770062974.
What it does not
Not the 42 minute Mariner 2 scan. Not Sacajawea’s 420 km frame. An absorption height is not a surface feature.
ExactnessApproximate
Form42
Unitkm
Strengthhard
When1974-02-05