Despite being our closest planetary neighbor, Venus is a fairly inhospitable place. It is about 100 times warmer than Earth, and spacecraft exploring its thick atmosphere are Broke in just 2 hours. However, Venus may have once had plate movements similar to those that occurred in the early days of Earth. This new discovery provides astronomers with several new scenarios to evaluate regarding the possibility of early life on Venus, its evolutionary past, and the history of the solar system. Here are the findings: The study was published Oct. 26 in the journal natural astronomy.
[Related: We finally know why Venus is absolutely radiant.]
inside studyUsing atmospheric data from Venus and computer modeling, the researchers showed that Venus’ current atmospheric composition and surface pressure could have arisen solely through early plate tectonics. This process is important for life and involves multiple continental plates pushing, pulling, and sliding beneath each other.
On Earth, these plate tectonics have been intensifying for billions of years. This process formed new continents and mountain ranges and triggered chemical reactions that stabilized Earth’s surface temperature. It also created an environment in which life could easily develop.
Venus moves in the opposite direction; Surface temperature is 867 degrees Fahrenheit, high enough to melt lead. Astronomers have always believed that Venus has a “stagnant lid.” This means that there is only a minimal amount of a given single plate on the surface of the planet. Gas remains trapped under the outer crustal lid.
The researchers used current data on Venus’ atmosphere as an endpoint for these models, starting by assuming that Venus has a stagnant lid throughout its existence. They could quickly see that the computer simulations that recreated the planet’s current atmosphere did not match Venus’ current location.
The team then simulated what would need to happen for Venus to reach its current state. In the end, when we accounted for the limited tectonic movements of Venus early in its history, followed by a model of the stagnant lid that exists today, the numbers matched almost exactly.
Because it is abundant, Nitrogen and carbon dioxide present in Venus’ atmosphere, the research team believes that Venus must have had plate tectonics about 4.5 to 3.5 billion years ago after the planet formed. They suggest that, similar to Earth, this early tectonic movement would have been limited in the number of plates moving around it and the amount they could move. This process would have occurred simultaneously on Venus and Earth.
“One of the big picture implications is that it is very likely that there were two planets in the same solar system at the same time operating in a plate tectonic regime. “It’s the same tectonic mode that made it possible,” said co-author Matt Weller, a planetary geophysicist at Brown University. stated in a statement.
[Related: A private company wants to look for life just above Venus.]
According to the team, this further supports the possibility that microbial life existed on ancient Venus. It also shows that at one point, both Earth and Venus were even more similar than scientists previously thought before they diverged. Both planets have the same size, mass, density, and volume And they live near the same sun.
This study also shows that the plate tectonics of all planets may simply be due to timing, so life itself could be a product of perfect timing.
“We’ve traditionally thought about the state of the Earth’s crust in terms of dualism: It’s either true or false, and it’s either true or false when it comes to the lifespan of the Earth,” study co-authors says Alexander Evans, a geobiologist and geophysicist at Brown University. stated in a statement. “This shows that planets can enter and exit different tectonic states, and that this may actually be quite common. Earth may be an outlier. No. This also means that there may be planets that become habitable and then become uninhabitable, rather than continuously habitable planets.”
Understanding the transition of tectonic states is important for future studies of nearby moons and distant exoplanets. Jupiter’s fourth largest moon Europa already shown Evidence of Earth-like plate tectonics.
“We’re still in the paradigm of using the surface of a planet to understand its history,” Evans says. “We have shown for the first time that the atmosphere may actually be the best way to understand parts of the planet’s very ancient history that are not preserved on the surface.”
future NASA’s da Vinci mission It will measure gases in Venus’ atmosphere and could help solidify the study’s results, and the details of how this happened could have important implications for Earth.
“It will be the next important step in understanding Venus, its evolution, and ultimately the fate of Earth,” Weller said. “What conditions would cause us to move in a Venus-like orbit? And what conditions would allow Earth to remain habitable? ”
