Below the altitude of 50 km the temperatures measured by the four probes are identical to within a few degrees. They are between 448 °C and 459 °C (838 °F and 858 °F) on the surface. The ground pressure is between 86. 2 bar and 94. 5 bar. Nephelometers identified three cloud layers with different characteristics. The most remarkable discovery was that the ratio of 36argon / 40argon isotopes much higher than in the atmosphere which seems to indicate that the genesis of the Venusian atmosphere is very different from that of Earth. The reconstituted trajectory of atmospheric probes was determined that the wind averaged a speed of 200 m/s in the middle cloud layer at 50 m/s at the base of these clouds and just 1 m/s at the ground. Overall data from airborne sensors confirmed, while specifying the data obtained by the Soviet space probe Venera program that preceded this mission.