Venus may remain active as tectonic motion discovery would indicate

(CNN) – With its thick, toxic atmosphere and temperatures high enough to melt lead, Venus looks like a dead planet.
However, new research suggests that the planet could still be geologically active.

And the kind of activity going on on Venus could give scientists a better idea of ​​what happens on planets outside our solar system, as well as what happened on early Earth.

A new analysis of radar images taken by NASA’s Magellan mission, which mapped the surface of Venus in the early 1990s, revealed signs of tectonic movement. This movement on the surface of Venus looks like blocks of crust that have moved against each other, much like chunks of broken ice. Ice blocks are the large chunks of floating ice that can be seen en masse together in polar seas, such as in the waters around Antarctica.

The study was published Monday in the journal Proceedings of the National Academy of Sciences.

“We have identified a previously unrecognized tectonic deformation pattern on Venus that is driven by interior motion just like it is on Earth,” said Paul Byrne, lead author of the study and associate professor of planetary sciences at Carolina State University. North, in a statement.

“Although it is different from the tectonics we see on Earth today, it is still evidence of the inner motion expressed on the planet’s surface,” Bryne said.

Previously, scientists believed that Venus had a solid, immovable outer shell, called the lithosphere, similar to that of Mars or our moon.

The Earth is unique because its lithosphere is broken, forming tectonic plates that move against each other, apart or below, on a hot mantle.

When Byrne and his research colleagues studied Magellan images taken from the lowlands of Venus, which make up most of the planet’s surface, they saw areas where large chunks of the lithosphere appeared to have moved. The blocks had separated, reunited, slid and turned, as if they were broken blocks of ice.

The researchers modeled this deformation of the surface and determined that this tectonics corresponds to the slow movement of the interior of the planet.

“These observations tell us that interior motion is driving surface deformation on Venus, similar to what happens on Earth,” Byrne said. ‘Plate tectonics on Earth is driven by convection in the mantle. The mantle is hot or cold in different places, it moves, and some of that movement moves to the surface of the Earth in the form of plate movement. It seems that a variation of this theme is also taking place on Venus. ‘

‘This is not plate tectonics like on Earth, since huge mountain ranges or giant subduction systems are not being created here, but it is evidence of deformation due to the inner flow of the mantle, which had not been demonstrated before on a global scale, ”Byrne explains.

The movement and deformation of the crustal blocks also point to something else: Venus is likely to remain geologically active today.

“We know that much of Venus has resurfaced volcanically over time, so some parts of the planet could be really young, geologically speaking,” Byrne said. “But several of the jostling blocks have formed in these young lava plains and deformed them, which means that the lithosphere fragmented after those plains were established. This gives us reason to think that some of these blocks may have moved geologically very recently, perhaps even today. ‘

Future missions to Venus could shed more light on this, given that the Magellan data is from the 1990s.

Studying this pattern on Venus could help researchers study exoplanets outside our solar system and even active tectonics on early Earth.

“The thickness of a planet’s lithosphere depends primarily on how hot it is, both on the inside and on the surface,” Byrne said.

‘The heat flux from the interior of the young Earth was up to three times greater than today, so its lithosphere could have been similar to what we see on Venus today: not thick enough to form plates that subduct, but thick enough to have been fragmented into blocks that pushed, pulled and moved. ‘

Although NASA hasn’t sent a mission to Venus in decades, our closest planetary neighbor will be a hub of activity in a few years. Three missions by NASA and the European Space Agency, announced this month, will observe the planet in high definition.
Venus may have been the first habitable world in our solar system, with an ocean and climate similar to Earth’s, but something happened to turn it into a toxic planet permanently shrouded in mist.

NASA’s DAVINCI + mission whose acronym stands for “Deep Atmosphere Venus Investigation of Noble gases, Chemistry and Imaging Plus”, that is, Investigation of the Deep Atmosphere of Venus of noble gases, chemistry and imaging. It will be dedicated to analyzing the atmosphere of Venus to determine how it formed and evolved. The initiative will also investigate the possibility of an ocean in the past of Venus.

Next, NASA’s VERITAS program, or “Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy” (ie “Emissivity, Radio Science, InSAR Radar, Topography and Spectroscopy”), will map the surface of the rocky planet in an effort to shed light on how it became so different from Earth. Our world is often called the twin of Venus because the planets are similar in size, but current comparisons stop there.

The VERITAS mission could also provide information on the geological history of Venus. The VERITAS orbiter, equipped with radar, could create a 3D topography, allowing scientists to determine the degree of volcanic activity on Venus through plate tectonic processes. The spacecraft could also study infrared emissions from the planet’s surface.

The European Space Agency will send EnVision to observe Venus and reveal any connection between its atmosphere and geological processes, as well as to investigate the mysterious history of the planet.

“It’s great to see renewed interest in exploring Venus, and I’m especially excited that these missions can test our key finding that the planet’s lowlands have been fragmented into shifting blocks of crust,” Byrne said. .