NASA Study Reveals Venus Crust Surprise

Fresh Perspectives on Venus' Crust: Unexpected Geological Similarities to Earth

Because of its thick clouds, blazing surface, and enigmatic geological activity, Venus—often referred to as Earth's hotter twin—has long enthralled astronomers. Researchers have revealed surprising information about Venus's crust in a new NASA-funded study that was published in Nature Communications. These findings contradict previous theories and provide new information on how the planet might function geologically.

Venus seems to have a solid outer crust with no discernible plate tectonics, in contrast to Earth, which is sculpted by the constant movement of tectonic plates. Folds, faults, and mountain ranges are the result of the continuous shifting and interaction of the Earth's crust, which is made up of vast, movable plates. Subduction, a process when one tectonic plate moves beneath another and descends into the mantle where it experiences metamorphism due to increased temperature and pressure, is a key aspect of Earth's crustal dynamics. In addition to recycling crustal material, this promotes volcanic activity and controls the Earth's surface geology.

In contrast, Venus appears to have a single, immobile crustal layer devoid of subduction zones or plate movement. The latest research, however, raises the possibility that crustal metamorphism may still occur on the planet—but through an internal mechanism rather than plate collisions. Under the direction of Justin Filiberto, deputy chief of NASA's Astromaterials Research and Exploration Science Division at the Johnson Space Center, the study simulates how the Venusian crust might behave under extreme heat and pressure using computer models.

The results imply that the crust of Venus is remarkably thin, with an average thickness of roughly 25 miles (40 kilometers) and a maximum thickness of 40 miles (65 kilometers). "That is shockingly thin, given the severe conditions on the planet," Filiberto said. According to the study, as Venus' crust increases over time, pressure and compositional changes cause the bottom layers to become so dense that they either melt or break off and sink into the mantle. Despite the lack of tectonic plates, this mechanism is similar to the metamorphic processes observed on Earth.

Earth's geology may be significantly impacted by this internal recycling of crustal material. Volcanic activity may be fueled by the return of water and volatile substances to the planet's interior due to crustal melting or sinking. "This provides us a new concept for how material returns to the planet's interior and another mechanism to generate lava and stimulate volcanic eruptions," Filiberto says. It changes the rules for how Venus's crust, atmosphere, and geology interact.

One of the main scientific objectives is still to determine whether Venus is still experiencing volcanic activity. Although previous studies and mapping of the planet's surface indicate that it should be volcanically active, concrete verification has proven difficult to get. The new model supports the notion that Venus may still be a geologically active planet by offering a tenable explanation for continuous volcanic activity in the absence of plate tectonics.

Scientists require direct data from Venus' surface and subsurface in order to evaluate and improve these models.

Thankfully, a number of future missions are planned to offer precisely that. NASA's VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) and DAVINCI (Deep Atmosphere Venus Investigation of Noble Gases, Chemistry, and Imaging) missions are designed to investigate Venus' surface and atmosphere in previously unheard-of detail. These initiatives will also be supported by the European Space Agency's EnVision mission, which is working with NASA to investigate the planet's surface composition, thermal properties, and potential indications of volcanic or tectonic activity.

Understanding Venus' geological past and present activity, as well as assessing the precision of the crustal metamorphism model, will depend heavily on these missions. "We do not really know how much volcanic activity there is on Venus," Filiberto states. Although research suggests there should be a lot, we would need additional information to be certain.

In conclusion, this innovative study ushers in a new era of Venusian science. It implies that even a static crust can experience transformative changes, challenging the conventional wisdom that plate tectonics is required for geological activity. Scientists are optimistic that the secrets of our blazing sister planet may soon be solved as future missions are set to investigate Venus in greater detail than has ever been possible.