Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought.

Two further experiments on the lander failed as well. Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes. References: 2, 6, 67, 274, 296, 428.

Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought. Therefore the landing gear of the following two landers (Venera-13/14) were equipped with tooth-shaped stabilisers.

Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.

The Venera-12 flyby bus continued in solar orbit and successfully used its Soviet-French ultraviolet spectrometer to study Comet Bradfield on 13 February 1980 (one year and two months after its Venus encounter). At that time the spacecraft was 190,373,790 km from Earth. References: 2, 6, 67, 274, 296, 428.