(CNN) When scientists recently took a closer look at archival images of the surface of Venus, they found something new: evidence of volcanic activity on Earth’s “twin.”
NASA’s Magellan spacecraft took the images in the early 1990s while it was orbiting our nearest planet, which is similar in size and composition to Earth.
A new analysis of the orbiter’s perspective of a region near the Venusian equator reveals a volcanic vent that changed shape and increased dramatically in size over eight months.
The crater images represent the first direct geological evidence of recent volcanic activity on the Venusian surface, according to the researchers. A study detailing the findings was published in the journal Wednesday Knowledgeand presented at the 54th Conference on Lunar and Planetary Sciences in The Woodlands, Texas.
The Magellan mission was the first to image the entire surface of Venus before the spacecraft was deliberately dropped into the planet’s hot and toxic atmosphere in 1994 to collect one final data set. But a new fleet of missions will be headed to Venus in a decade, incl Truth, honestyVenus emissivity, radio science, InSAR, topography, and message spectroscopy.
Active volcanic landscape
The probe will use its instruments to unlock the secrets behind a planet similar in size to Earth covered in volcanic plains and an inhospitable atmosphere.
“I was inspired by NASA’s VERITAS mission selection to look for recent volcanic activity in the Magellan data,” study lead author Robert Herrick, a research professor at the University of Alaska Fairbanks and member of the Veritas science team, said in a statement. .
“I really didn’t expect it to work, but after about 200 hours of manually comparing images from different Magellan orbits, I noticed two images of the same area eight months apart showing geological changes caused by volcanic eruptions.”
Herrick detects a change in the image of the Atla Reggio, a large plateau region that includes the two largest volcanoes on Venus, Ozza Mons and Maat Mons. Both are similar to the two largest volcanoes on Earth, Herrick said, but because they have a lower slope, the two volcanoes on Venus are more spread out.
Note that the vent on the north side of the domed volcano that is part of Maat Mons changed hands between February and October 1991.
Images of the Magellan vent from February show a circular vent spanning less than 1 square mile (2.2 square kilometers) with steep inner sides and areas of drained lava on the slopes.
Eight months later, the spacecraft took another image showing a very different and distorted looking hole, almost double in size and almost full of a lava lake.
Despite the apparent differences, the two images were taken from opposite angles and perspectives and at a much lower resolution than the images captured by cameras on today’s spacecraft.
Venus 3D mapping
Herrick worked with Scott Hensley, project Veritas scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, to create a computer model of the vent to determine the likely cause of the changes.
“Only two simulations match the images, and the most likely scenario is that volcanic activity occurred on the surface of Venus during the Magellan mission,” Hensley said. “While this is just a data point for the entire planet, it confirms recent geological activity.”
Researchers believe that the pyroclastic flows that Magellan witnessed in 1991 are similar to those ejected by the Kilauea eruption in Hawaii in 2018.
“It’s looking for a needle in a haystack with no guarantee it’s there,” says Herrick. “Finding a change that can be clearly confirmed as real was an absolute surprise. We’re pretty sure that Venus is volcanically active, but we don’t know if eruptions happen every few months or years or once every 10,000 years or so. All can be Options according to current data. Barring extreme luck, we now know that the frequency is every few months or so, similar to Earth’s large family of basaltic volcanoes such as Hawaii, the Galapagos Islands, the Canary Islands, etc.”
While it’s possible that the quake caused the walls of the volcanic vent to collapse, researchers believe the activity could also lead to an eruption.
Volcanoes act like windows into a planet’s interior, allowing scientists to understand more about the factors that influence its ability to become a habitable world. Missions like VERITAS will help scientists gain a better understanding of Venus, just as Magellan did decades ago.
The new mission will be equipped with a radar to create a 3D global map of Venus and capture details about its surface composition, gravitational field and what happened in the planet’s past.
“Venus is a mysterious world, and Magellan has brought up so many possibilities,” Jennifer Witten, VERITAS Associate Principal Investigator and Assistant Professor of Earth and Environmental Sciences at Tulane University in New Orleans, said in a statement. “Now that we’re absolutely certain that the planet experienced a volcanic eruption just 30 years ago, this is a small preview of the incredible discoveries VERITAS will make.”
