Vast and enigmatic geological features on the surface of Venus, known as coronae, provide intriguing evidence suggesting that the planet may exhibit tectonic activities similar to those observed on Earth. In new research spearheaded by scientists utilizing data collected over three decades ago by NASA’s pioneering Magellan mission, it has become increasingly clear that the geological machinery of Venus may be more active than previously understood. While Venus does not have tectonic plates akin to Earth, the findings indicate that the planet’s surface is still undergoing transformation due to dynamic processes driven by molten materials from below.
Researchers focused on coronae, which are unique geological formations found on Venus. These structures, often quasi-circular in shape and ranging widely in diameter from tens to hundreds of miles, are hypothesized to form where molten rock from the planet’s mantle rises towards the surface. The mechanisms at play beneath the lithosphere, which includes the crust and the upper mantle, have long intrigued planetary scientists. Typically, coronae are characterized by their oval shape and concentric fracture systems, with hundreds identified across Venus’ surface.
The groundbreaking study published in the journal Science Advances reveals compelling evidence of ongoing geological processes shaping many coronae. By reevaluating data gathered during the Magellan mission, which provided the most comprehensive gravity and topographic data of Venus to date, researchers have uncovered signs of continued activity both at and beneath these features. The lead author of the study, Gael Cascioli, an assistant research scientist at the University of Maryland, underscores the relevance of this research for understanding both Venus and early Earth, noting that coronae may have existed on our planet in its formative years before the establishment of plate tectonics.
The Magellan spacecraft, which operated in the early ’90s, utilized its sophisticated radar systems to penetrate the dense atmosphere of Venus, mapping its mountain ranges and plains with remarkable precision. Among the geological wonders captured by the spacecraft were coronae—intriguing formations whose origins remained a mystery for many years. Following the initial observations, subsequent research has shown that a significant number of these structures are often located in areas where the lithosphere appears to be thinner and where heat flow from the interior of Venus is notably high.
The findings from the recent study illuminate the potential for various ongoing geological processes, including those that may have been active during the early stages of Earth’s geological history. Coauthor Anna Gülcher highlights the abundance of coronae on Venus, suggesting that their sheer size and frequency indicate that multiple mechanisms are likely responsible for their formation. The study indicates that these processes, previously thought to be exclusive to Venus, may have parallels in the ancient formative years of Earth’s geology.
To explore the origins of a subset of the studied coronae, the research team employed advanced three-dimensional geodynamic models. These models simulate different formation scenarios induced by thermal plumes and compare these scenarios against the data acquired through Magellan. The gravity data proved pivotal for identifying less dense and buoyant plumes located below the surface, a distinction that could not have been made using topography data alone. The study scrutinized 75 coronae, determining that 52 of them likely conceal buoyant mantle material beneath, which actively contributes to tectonic processes.
One of the key tectonic processes identified in the study is akin to the concept of subduction found on Earth, where one tectonic plate slides beneath another. This movement can result in common geological phenomena such as earthquakes or volcanic activity, as melting rock is recycled back to the surface through various vents. On Venus, however, subduction around coronae unfolds quite differently. As a buoyant plume ascends, it causes surrounding surface material to be displaced, leading to the formation of depressions as that material is pushed downward back into the mantle.
Additionally, another tectonic mechanism referred to as lithospheric dripping may also be at work on Venus. In this scenario, cooler, denser materials from the lithosphere descend into the hot mantle. The study points out that the presence of molten rock beneath denser segments of the lithosphere potentially fuels volcanism in those regions, adding another layer of complexity to understanding the planet’s geological activities.
The research marks a notable return to the analysis of Magellan’s data, revealing that Venus possesses geologic processes that exhibit a strength and frequency reminiscent of Earth’s own geological phenomena. Following the analysis, scientists have recently identified the existence of active volcanoes using enhanced radar images, providing direct evidence of volcanic activity on the planet’s surface, including extensive lava flows from prominent geological features like Maat Mons, Sif Mons, and Eistla Regio.
Despite the strides made through these discoveries, the authors of the current study emphasize that sharper, higher-resolution data is necessary for a complete understanding of the tectonic processes that drive the formation of coronae. The forthcoming VERITAS mission, which will launch no earlier than 2031, promises to enhance gravitational mapping of Venus, potentially doubling or quadrupling the resolution compared to existing data. This leap in detail could fundamentally reshape our comprehension of Venusian geology and its broader implications for understanding the early conditions on Earth.
VERITAS, managed by NASA’s Jet Propulsion Laboratory, will utilize synthetic aperture radar technology to generate detailed three-dimensional maps of the planet’s surface, along with a near-infrared spectrometer designed to analyze the composition of Venus’ surface materials. By measuring the gravitational field of Venus, the mission aims to unearth the structure of the planet’s interior, providing crucial insights into areas of surface activity and possibly advancing our understanding of planetary formation processes.
As we stand on the verge of new discoveries propelled by missions like VERITAS, the intricate geological dynamics of Venus not only challenge our perceptions of our neighboring planet but also enrich our understanding of the processes that shaped our own Earth. With ongoing research revealing more about this enigmatic world, the anticipation builds for what further explorations may uncover.
Subject of Research: Tectonic processes on Venus
Article Title: A spectrum of tectonic processes at coronae on Venus revealed by gravity and topography
News Publication Date: 14-May-2025
Web References: NASA’s Magellan Mission, VERITAS Mission Overview
References: DOI link
Image Credits: NASA/JPL
Keywords
Venus, coronae, tectonics, Magellan mission, VERITAS, geodynamics, geology, volcanic activity, planetary science, Earth-like processes, magma plumes, lithosphere.
