Scientists have found some of the strongest evidence yet that there is volcanic activity on Venus. Because the planet is a close neighbor to Earth and originally had water on its surface, a big question This is why its landscape is hellish while that of the Earth is habitable. Knowing more about its volcanic activity could help explain its evolution – and that of the Earth.
Scientists know that Venus is covered in volcanoes, but whether or not any of them are still active has long been debated. Now researchers have discovered that at least one of them probably is, by examining radar images of the planet’s surface collected by NASA’s Magellan spacecraft between 1990 and 1992. They have determined that a volcanic vent located in the Atla Regio region of Venus, which contains two of the largest volcanoes on the planet, changed shape between two images taken eight months apart, suggesting an eruption or flow of magma below the vent. The scientists reported their findings on March 15 to Science1 and presented them at the Lunar and Planetary Science Conference in Woodlands, Texas on the same day.
It’s a “striking discovery,” says Darby Dyar, an astronomer at Mount Holyoke University in South Hadley, Massachusetts. This brings the space research community closer to understanding how Venus works, adds Dyar, who is also deputy principal investigator for the VERITAS mission to Venus, which is overseen by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Washington. California. and aims to map the surface of the planet after 2030. “The whole question of whether there is active volcanism on the surface of Venus suffers from a lack of data,” she adds.
A hellish planet
Gathering evidence that the planet is volcanically active has not been easy. Venus’ thick atmosphere – 100 times the mass of Earth – and high temperatures – 450 ºC – make it difficult for rovers and other probes to explore the surface. So far, the most reliable data scientists have collected comes from the Magellan spacecraft.
Robert Herrick, a geophysicist at the University of Alaska Fairbanks, and Scott Hensley, a JPL radarologist who is also part of the VERITAS team, analyzed full-resolution radar images captured by Magellan of areas suspected of volcanic activity.
The challenge was that Magellan imaged the planet in three different cycles during its 24-month mission. During each cycle, it pointed its radar at a different angle relative to the surface of Venus. For the scientists to look for changes on the surface over time, they had to overlay the images from different angles and find overlaps in the terrain to line them up.
Herrick likens the problem to flying in multiple directions through the Grand Canyon in Arizona and then trying to map its surface while looking at the opposite canyon walls. “Trying to find the same things in these images becomes a little more difficult,” he says.
The low resolution of Magellan’s images added another layer of complexity. “You look at the surface, where a football pitch is a single pixel,” he adds.
This worries Scott King, a geophysicist at Virginia Tech University in Blacksburg who studies Venus. He wonders if the images are strong enough evidence to convince skeptics that Venus is volcanically active. “The proof is in the eye of the beholder,” he says.
Herrick and Hensley acknowledge this limitation in their data. But they also say they are not aware of any equivalent event on Earth that could cause the changes they observed without volcanic activity, although they cannot rule out the possibility that something else may have. to be responsible.
King has no trouble believing that the planet has volcanic activity. However, he hopes that upcoming missions on Venusincluding VERITAS, will provide the necessary data to convince everyone.
An unknown planet
VERITAS, however, has been delayed – so King may be waiting longer than initially thought. NASA had planned to launch the mission in 2028, but the agency had to reallocate funds to deal with the delay of Psyche, another mission that will study a metal-rich asteroid orbiting the Sun between Mars and Jupiter. NASA currently has no funds planned in the coming years for VERITAS, and if it restores funding, the mission would launch no earlier than 2031.
Launching VERITAS after 2030 could cause problems for other missions, Dyar says. Ideally, the topographic data collected by VERITAS would have provided NASA’s DAVINCI and the European Space Agency’s EnVision with information to help them better target the areas they plan to explore. DAVINCI, slated for launch in 2029, aims to drop a probe into Venus’s atmosphere, and EnVision, slated for launch in the early 2030s, is intended to take high-resolution radar images of the surface of Venus. planet.
Studying Venus could not only help researchers better understand how Earth works, but also help them learn more about exoplanets beyond the solar system. “We are discovering hundreds, thousands of exoplanets,” Dyar says. And many of them seem to resemble Venus, she adds.
Many space missions have targeted Mars recently, although overall Venus is much more Earth-like than the Red Planet. Herrick hopes the new findings will motivate people to look to Venus and launch VERITAS in time. “Venus is really Earth’s brother,” he says.
This article is reproduced with permission and has been first post on March 15, 2023.