1978.5.20 PIONEER 12 carried out its explorative mission on Venus after successful launch

The US launched SLV-3D space vehicle to put Pioneer 12 with the mass of 582 kg To begin the detecting mission of Venus.

On December 4, 1978, PIONEER 12 entered the oval orbit of Venus and began to investigate the atmosphere, environment, and the surface of Venus. PIONEER 12 also calculated the shape and density of Venus and transmitted the data back to the earth.

According to the information attain by PIONEER 12, we know that the surface of Venus is covered by a cloudy atmosphere and there are canyons and two volcanoes on its surface. The measurement indicated that the ground temperature of Venus reached to 482℃.

PIONEER 12 continued to orbit in the orbit of Venus eight months after the completion of mission. Till October 8, 1992, it fell down to the atmosphere of Venus due to the depletion of energy.