Venera 11 was a Soviet space probe launched on September 9, 1978, as part of the Venera program to explore the planet Venus. It successfully landed on Venus on December 1, 1978, and transmitted data back to Earth for about 95 minutes, providing valuable information about the planet's atmosphere and surface conditions. The probe was equipped with scientific instruments to measure temperature, pressure, and chemical composition. It revealed that Venus has a thick atmosphere composed mainly of carbon dioxide, with clouds of sulfuric acid, and surface temperatures reaching around 450 degrees Celsius, making it one of the hottest planets in the solar system.