What is NASA’s surprising discovery on Venus?

10:10 am

A new analysis of radar data from NASA’s Magellan mission in the 1990s reveals two volcanic eruptions on Venus in the early 1990s.

specific, Changes detected on the surface indicate the formation of new rocks from lava flows associated with volcanoes that erupted as the spacecraft orbited the planet. Magellan, operated by NASA’s Jet Propulsion Laboratory, mapped 98% of Venus’ surface between 1990 and 1992, and the images created remain the most detailed of Venus to date.

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

This latest discovery builds on the landmark 2023 discovery of Magellan Synthetic Aperture Radar images that revealed changes in a vent associated with the Maat Mons volcano near the equator of Venus.

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 molten rock flowing from beneath the surface of Venus, filling the vent crater and extending down the vent’s slopes.

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

In 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 the thick cloud cover of Venus, then bounced off the planet’s surface and returned to the spacecraft. These reflected radar signals, called backscatter, carry information about the rock surface materials encountered.

The two sites studied are the Sword Mons volcano in Estella Reggio and the western part of Niobi Planitia, which is home to numerous volcanic formations. By analyzing backscatter data from both sites in 1990 and again in 1992, the researchers found that the strength of the radar signal increased along certain paths during subsequent orbits. These changes indicate the formation of new rocks, most likely hardened lava from the volcanic activity that occurred during that two-year period. But they also took into account other possibilities, such as the presence of small dunes (formed by wind-blown sand) and atmospheric effects that could interfere with the radar signal.

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

“We interpret these signals as flows along volcanic slopes or plains that can deflect around obstacles such as shield volcanoes as fluids.“After ruling out other possibilities, we confirmed that our best explanation is that these are fresh lava flows,” said study co-author Marco Mastrogiseppe of Sapienza University in Rome.

Using flows on land for comparison, the researchers estimate that the depth of new rocks placed at both sites is between 3 and 20 meters on average. They also estimate that the Mons eruption produced about 30 square kilometers of rock, enough to fill at least 36,000 Olympic-size swimming pools. The eruption of Niobe Planitia volcano produced approximately 45 kilometers of rock, which would fill 54,000 Olympic-size swimming pools. By 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-sized swimming pools.