Was Venus once warm and wet? New study of lava flow suggests not

Houston, TX and Columbia, MD—October 7, 2019.  A new study of the Ovda Fluctus lava flow on Venus indicates that it is made of basaltic lava. This discovery weakens the notion that Venus might once have been Earth-like with an ancient ocean of liquid water.

Magellan Radar mosaic of Venus; the Ovda Fluctus lava flow at the arrow’s point. Image credit: NASA

Previous studies suggested that early Venus was once warm and wet based on the chemistry of its atmosphere and the presence of highlands. These highlands were thought to be formed of granitic rock, like Earth’s continents, which required oceans of water to form.

Scientists at the Lunar and Planetary Institute (LPI), including undergraduate student intern Frank Wroblewski from Northland College, find that a volcanic flow on Venus’ Ovda Regio highlands plateau is composed of basaltic lava, calling into question the idea that the planet might once have been Earth-like with an ancient ocean of liquid water.

The LPI team re-mapped the Ovda Fluctus lava flow using radar data. They discovered that the flow is not granitic as was expected from its location, but is more likely made up of basalt rock which can form with or without water. The result has potentially significant implications for the evolutionary history of Venus. The new map and results are published in the Journal of Geophysical Research: Planets.

Close-up of the lava flow – dark line shows its margin. Image credit: NASA

“We know so little about Venus’ surface,” says team member Dr. Allan Treiman, a Universities Space Research Association (USRA) scientist at the Lunar and Planetary Institute (LPI). “If the Ovda Regio highlands are made of basaltic rock as is most of Venus, they were likely squeezed up to their current heights by internal forces, possibly like mountains which result from plate tectonics on Earth.”

This work began in 2018 as part of the LPI’s Summer Intern Program (https://www.lpi.usra.edu/lpiintern/), which brings competitively selected undergraduate students to Houston to do cutting-edge research with scientists from the LPI and the Astromaterials Research and Exploration Science (ARES) Division of NASA Johnson Space Center. LPI is operated by the Universities Space Research Association (USRA). The paper can be viewed online at: https://doi.org/10.1029/2019JE006039.

About USRA

Founded in 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA) is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs, under Federal funding. It also operates the Lunar and Planetary Institute under funding from the National Aeronautics and Space Administration (NASA). Moreover, USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise. More information about USRA is available at www.usra.edu.

About LPI

The Lunar and Planetary Institute (LPI), operated by Universities Space Research Association, was established during the Apollo program to foster international collaboration and to serve as a repository for information gathered during the early years of the space program. Today, the LPI is an intellectual leader in lunar and planetary science. The Institute serves as a scientific forum attracting world-class visiting scientists, postdoctoral fellows, students, and resident experts; supports and serves the research community through newsletters, meetings, and other activities; collects and disseminates planetary data while facilitating the community’s access to NASA science; and engages and excites, and educates the public about space science and invests in the development of future generations of explorers. The research carried out at the LPI supports NASA’s efforts to explore the solar system. More information about LPI is available at www.lpi.usra.edu.