Ongoing volcanic activity detected on Venus with archival data

May 27. () –

A new analysis of radar data from NASA’s Magellan mission from the 1990s has revealed that two volcanoes erupted on Venus at the beginning of the last decade of the last century.

Specifically, changes detected on the surface that indicate the formation of new rocks from lava flows linked to volcanoes that erupted while the spacecraft orbited the planet. Managed by NASA’s Jet Propulsion Laboratory, Magellan mapped 98% of the surface of Venus between 1990 and 1992, and The images it generated remain the most detailed of Venus to date.

“Using these maps as a guide, our results show that Venus may be much more volcanically active than previously thought,” he said. it’s a statement Davide Sulcanese of the University d’Annunzio in Pescara, Italy, who led the study. “By analyzing the lava flows we observed in two places on the planet, we have discovered that volcanic activity on Venus could be comparable to that on Earth.”

This latest discovery builds on the landmark 2023 discovery of Magellan Synthetic Aperture Radar images that revealed changes to a vent associated with the Maat Mons volcano near Venus’ equator. The radar images turned out to be the first direct evidence of a recent volcanic eruption on the planet. By comparing radar images of Magellan over time, the authors of the 2023 study detected changes caused by the outflow of molten rock from Venus’ subsurface filling the vent crater and spilling down the slopes of the vent.

Scientists study active volcanoes to understand how a planet’s interior can shape its crust, drive its evolution, and affect its habitability. The discovery of recent volcanism on Venus provides valuable information about the planet’s history and why it took a different evolutionary path than Earth.

For the new study, published in the journal Nature Astronomy, the researchers also focused on archival data from the Magellan probe’s synthetic aperture radar. The radio waves sent by the radar traveled through Venus’ thick cloud cover, then bounced off the planet’s surface and returned to the spacecraft. These reflected radar signals, called backscatter, carried information about the rock surface material they encountered.

The two sites studied were the Sif Mons volcano in Eistla Regio and the western part of Niobe Planitia, which is home to numerous volcanic formations. By analyzing backscatter data received from both locations in 1990 and again in 1992, the researchers found that the radar signal strength increased along certain trajectories during subsequent orbits. These changes suggested the formation of new rock, most likely solidified lava from volcanic activity that occurred during that two-year period. But they also considered other possibilities, such as the presence of microdunes (formed from windblown sand) and atmospheric effects that could interfere with the radar signal.

To help confirm new rocks, researchers analyzed altimetry (surface height) data from Magellan to determine the slope of the topography and locate obstacles around which lava would flow.

“We interpret these signals as flows along volcanic slopes or plains that can deflect around obstacles like shield volcanoes like a fluid,” said study co-author Marco Mastrogiuseppe of Sapienza University of Rome. “After ruling out other possibilities, “We confirm that our best interpretation is that these are new lava flows.”

Using flows on Earth as a comparison, the researchers estimate that the new rock placed in both locations is between 3 and 20 meters deep, on average. They also estimate that the Sif Mons eruption produced around 30 square kilometers of rock, enough to fill at least 36,000 Olympic-sized swimming pools. The Niobe Planitia eruption produced approximately 45 kilometers of rock, which would fill 54,000 Olympic swimming pools. For comparison, the 2022 eruption of Mauna Loa in Hawaii, the largest active volcano on Earth, produced a lava flow with enough material to fill 100,000 Olympic swimming pools.