Venus is an inhospitable world characterized by scorching temperatures reaching several hundred degrees Celsius and a complete absence of surface oceans. For a long time, planetary scientists assumed that the planet was entirely geologically dormant. However, recent research indicates that Venus remains surprisingly alive from a geological standpoint and even hosts active volcanoes. Among its prominent geological features, rift valleys indicative of tectonic activity can be vast and comparable in scale to terrestrial counterparts like the African Rift Valley, sometimes stretching up to ten thousand kilometers across the planet’s surface.
Unveiling the dynamic interior and active tectonics of Venus
Despite the clear presence of these extensive fault systems, the exact timing of their formation has remained uncertain. Geoscientists previously believed that these rifts originated more than one hundred million years ago, classifying them primarily as ancient vestiges of the planet’s distant past. Addressing this longstanding ambiguity, researchers at ETH Zurich, led by geodynamics professor Taras Gerya alongside lead author Xi Yang, sought to reevaluate the timeline and dynamics of Venusian tectonics using advanced modeling techniques to determine whether these geological features could be of a more recent origin.
To tackle the complexities of Venusian geology, Yang and his team utilized an innovative computer model designed to simulate three-dimensional, high-resolution rifting processes for the first time. This methodological advancement enabled the researchers to accurately replicate rift structures in their simulations, yielding much more precise explanations for how these formations develop compared to older, two-dimensional models that relied heavily on simplified material assumptions. The new simulations reveal that prominent ridges, known as rift flanks, form naturally along the margins of rift valleys when the systems are young and actively moving or have only recently ceased movement.
Furthermore, the computer models suggest that these venusian rifts widen at a significantly faster rate than previously estimated, operating at speeds between three and ten centimeters per year. The simulations also demonstrate that the flanks of these faults tend to flatten out rapidly once tectonic movement stops, meaning older fault systems naturally feature less steep and narrower flanks. Unlike Earth, where weathering and erosion gradually wear down geological formations, the flanks on Venus subside primarily as a result of crustal relaxation over time.
Observational data strongly support these simulation findings, as wide and elevated fault walls are clearly visible in the archival surface imagery captured by NASA’s Magellan spacecraft during its mission in the 1990s. By combining these observational datasets with their novel computer models, the researchers conclude that Venus possesses a far more dynamic interior than previously acknowledged. Gerya notes that these findings fundamentally enhance our ability to accurately assess ongoing tectonic activity across the planet.
Implications for future space missions and rocky exoplanet research
The insights derived from the ETH research team’s model provide critical tools that could help pinpoint active regions on Venus, guiding future exploration efforts and identifying prime locations for detailed investigation. Enhanced understanding of Venusian tectonics also broadens our general knowledge regarding the formation and evolution of rocky planets, potentially uncovering crucial clues to improve the detection and characterization of rocky exoplanets orbiting distant stars.
With interest in our planetary neighbor currently surging, both NASA and ESA are actively preparing multiple missions aimed at comprehensive exploration. ETH geophysics professors Paul Tackley and Taras Gerya, together with their international collaborators, are directly contributing to ESA’s upcoming EnVision mission by developing specialized instruments for the orbital spacecraft. Scheduled for launch in the early 2030s, this ambitious mission will thoroughly analyze Venus from its deep core all the way up to its upper atmosphere.
The study is published in Nature Geoscience.
