New Ideas for an Old Problem: Observations and Science 1980–2020

Abstract

The 1970s were an extraordinarily productive time for Venus research, with space missions making the first direct measurements in its atmosphere and on its surface. The Soviet Union was spectacularly successful, landing a series of spacecraft that sent home the first up-close views of our neighboring world. Venera 7 became the first spacecraft to successfully soft-land on another planet and transmit a signal back to Earth; it made in situ environmental measurements of a broiling, 475^∘C surface with a pressure ninety times that at sea level on Earth. The follow-up Venera 8 mission proved that the lower atmosphere of Venus was relatively clear and that its surface rocks were compositionally similar to the basaltic rocks of our own planet. In October 1975, Venera 9 radioed back to Earth the first photographs taken at the surface of Venus, revealing an expanse of plate-like rocks showing no evidence of erosion. Later in the decade, the Americans flew both spacecraft in the Pioneer Venus series, one of which continued relaying data back to Earth for almost 15 years. These missions yielded new insights into the composition and structure of the Venus atmosphere, as well as providing the first global map of the planet’s surface, gleaned from radar measurements.