Voyager 1 image showing lava flows radiating from Ra Patera at lower left (March 5, 1979).
Ra Patera is an extraterrestrialvolcano located on Io. An active volcano, it was first studied in 1979 via Voyager stereo imagery to determine its geology, topography, and the source of its eruptions. When first discovered, the mountain reached about one kilometer in height and featured numerous lava flows of either low viscosity or "high eruption rates". It is possibly a liquid sulfur-erupting volcano.