Volcanic exercise on Venus’ evil twin Earth revealed in NASA Magellan information

NASAs selection of the VERITAS mission inspired me to look for recent volcanic activity in Magellan data, said Robert Herrick, a research professor at the University of Alaska Fairbanks and member of the VERITAS science team, who led the search of the archival data. I didnt really expect to be successful, but after about 200 hours of manually comparing the images of different Magellan orbits, I saw two images of the same region taken eight months apart exhibiting telltale geological changes caused by an eruption.

The search and its conclusions are described in a new study published in the journal Science. Herrick also presented the findings at the 54th Lunar and Planetary Science Conference in the Woodlands, Texas, on March 15.

Maat Mons is displayed in this computer-generated, three-dimensional perspective of the surface of Venus. The viewpoint is located 634 kilometers (393 miles) north of Maat Mons at an elevation of 3 kilometers (2 miles) above the terrain. Lava flows extend for hundreds of kilometers across the fractured plains shown in the foreground, to the base of Maat Mons. NASA Magellan mission synthetic aperture radar data is combined with radar altimetry to develop a three-dimensional map of the surface. The vertical scale in this perspective has been exaggerated 10 times. Credit: NASA/JPL

Modeling a Volcano

The geological changes Herrick found occurred in Atla Regio, a vast highland region near Venus equator that hosts two of the planets largest volcanoes, Ozza Mons and Maat Mons. The region has long been thought to be volcanically active, but there was no direct evidence of recent activity. While scrutinizing Magellan radar images, Herrick identified a volcanic vent associated with Maat Mons that changed significantly between February and October 1991.

In the February image, the vent appeared nearly circular, covering an area of less than 1 square mile (2.2 square kilometers). It had steep interior sides and showed signs of drained lava down its exterior slopes, factors that hinted at activity. In radar images captured eight months later, the same vent had doubled in size and become misshapen. It also appeared to be filled to the rim with a lava lake.

Altitude data for the Maat and Ozza Mons region on the Venus surface is shown at left, with the area of study indicated by the black box. At right are the before (A) and after (B) Magellan observations of the expanded vent on Maat Mons, with possible new lava flows after an eruptive event. Credit: Robert Herrick/UAF

But because the two observations were from opposite viewing angles, they had different perspectives, which made them difficult to compare. The low resolution of the three-decade-old data only made the work more complicated.

Herrick teamed up with

The scientists liken the size of the lava flow generated by the Maat Mons activity to the 2018 Kilauea eruption on the Big Island of Hawaii.

This annotated, computer-simulated global map of Venus surface is assembled from data from NASAs Magellan and Pioneer Venus Orbiter missions. Maat Mons, the volcano that has exhibited signs of a recent eruption, is within the black square near the planets equator. Credit: NASA/JPL-Caltech

Magellans Legacy

Herrick, Hensley, and the rest of the VERITAS team are eager to see how the missions suite of advanced science instruments and high-resolution data will complement Magellans remarkable trove of radar imagery, which transformed humanitys knowledge of Venus.

Venus is an enigmatic world, and Magellan teased so many possibilities, said Jennifer Whitten, associate deputy principal investigator of VERITAS at Tulane University in New Orleans. Now that were very sure the planet experienced a volcanic eruption only 30 years ago, this is a small preview for the incredible discoveries VERITAS will make.

VERITAS will use state-of-the-art synthetic aperture radar to create 3D global maps and a near-infrared spectrometer to figure out what the surface is made of. The spacecraft will also measure the planets gravitational field to determine the structure of Venus interior. Together, the instruments will offer clues about the planets past and present geologic processes.

And whereas Magellans data was originally cumbersome to study Herrick said that in the 1990s they relied on boxes of CDs of Venus data that were compiled by NASA and delivered in the mail VERITAS data will be available online to the science community. That will enable researchers to apply cutting-edge techniques, such as

More About the Mission

In 2021, NASA chose the VERITAS and DAVINCI missions as their next ventures to Venus under the Discovery Program. VERITAS has collaborated with several organizations, including Lockheed Martin Space, the Italian Space Agency, the German Aerospace Center, and Frances Centre National dtudes Spatiales. The Planetary Missions Program Office at NASAs Marshall Space Flight Center in Huntsville, Alabama, manages the Discovery Program for NASAs Science Mission Directorates Planetary Science Division in Washington.