New computer models of Venus’s surface features, including ridges likely caused by volcanic activity, have determined that the second rock from the Sun remains geologically active to this day.
The ETH Zurich research team behind the new Venusian models, which suggest that Venus may still have active volcanoes, said their findings could help planned NASA and ESA missions select the most promising targets. The new models could also help in the search for rocky planets outside of our Solar System, including those that may support life.
Venus Previously Considered Geologically Dormant for Over 100 Million Years
Venus has long fascinated planetary scientists due to its similarities. For example, the planet’s mass and circumference make it roughly 95% the same size as Earth overall. However, although Venus’ elliptical orbit brings it closer to Earth than any other planet in the Solar System, its extreme surface temperatures and toxic atmosphere make it inhospitable to life as we know it.
Ground and space observations have detected rift valleys on Venus’s surface, which the research team notes indicate tectonic activity. Some can measure up to 10,000 kilometers and resemble the longest ridges on Earth. Although the timing of Venus’ rift formations remains uncertain, the team said most scientists have typically considered the planet to be geologically dormant. Some estimates have put their formation more than 100 million years ago.
Curious if data captured by space and ground-based observatories could provide enough information to answer the timing question, a research team from ETH led by Taras Gerya, a Professor of Geodynamics at the Department of Earth and Planetary Sciences, decided to plug that data into computer models. According to their results, the reports of Venus’ demise may have been greatly exaggerated.
Models Reveal Planet Likely Supports Active Volcanoes
Working under Professor Gerya’s supervision, Master’s candidate and lead author of the paper detailing the team’s work, Xi Yang, and colleagues employed computer models to simulate the planet’s rifts in high-resolution and 3D. The team said these models allowed them to “accurately replicate these rift structures” in a level of detail never achieved. The data also allowed them to perform simulations to best determine how they originally formed.
Critically, the team notes that earlier attempts to model Venus’ tectonic history and potential ongoing activity had been mostly two-dimensional. Yang’s team also said those earlier models had relied on “simplified material assumptions” that his team was able to expand upon.
After completion, the models yielded several compelling results. First, they indicated that the broad ridges geologists call ‘rift flanks’ form along the edges of rift valleys at a time when the rifts are still “geologically young.” Specifically, the team’s models suggested that these flanks formed when Venus was still either actively moving or had only recently stopped moving.
A closer look at the simulations also suggested that these geological rifts open over a much shorter time scale than previously assumed, with an estimated rate between 3 and 10 centimeters per year. The models also indicated that rift flanks tend to flatten very quickly once the movement ends.
“The older the rift system, the less steep and narrow its flanks,” they explained.
A comparison to erosion patterns on Earth also supported a more recent time frame for the rift flank formations spotted on the Venusian surface from the Magellan probe during its 1990s mission. The team said that these formations and their models suggest that “Venus remains an active planet with a more dynamic interior than had been previously believed.”
“Venus remains geologically “alive” and even hosts active volcanoes,” they explained.
Planned NASA & ESA Missions Could Confirm Models
When discussing the implications of their work, Professor Gerya said the findings “help us to better assess the tectonic activity on Venus.” The team noted that their models could also guide future missions by pinpointing potentially active regions worthy of closer examination.
The ETH team said their study also has planetary formation implications, particularly for rocky planets like Venus and Earth. Such data could prove valuable in the search for rocky exoplanets, including the type that may host life.
Moving forward, the study authors noted that NASA and the European Space Agency (ESA) are actively preparing “multiple missions” to explore Venus in further detail. ETH geophysics professors Paul Tackley and Gerya, and their team of collaborators, are already participating in ESA’s EnVision mission.
The work includes developing instruments for the orbiter to analyze the surface in greater detail. Scheduled for launch in the early 2030s, the team said that EnVision will explore the planet more thoroughly than previous efforts “from its core to its upper atmosphere.”
The study “Recent active rifting on Venus revealed by wide rift flank uplifts” was published in Nature Geoscience.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org.