National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Pioneer Venus 1
Pioneer Venus 1 (click to enlarge)

Pioneer Venus 1
Date: 20 May 1978

During a 14-year orbit of Venus, Pioneer Venus 1 used radar to map the surface at a resolution of 75 km (47 miles). It found the planet to be generally smoother than Earth, though with a mountain higher than Mt. Everest and a chasm deeper than the Grand Canyon. The orbiter also found Venus to be more spherical than Earth, consistent with the planet's much slower rotation rate (one Venus day equals 243 Earth days). It confirmed that Venus has little, if any, magnetic field and found the clouds to consist mainly of sulfuric acid. Measurements of this chemical's decline in the atmosphere over the course of the mission suggested that the spacecraft arrived soon after a large volcanic eruption, which may also account for the prodigious lightning it observed.

Credit: NASA

Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 9 Dec 2011