Scientists have discovered a new geological connection between Earth and Venus

Ishtar Land is a complex geological region on Venus. New research suggests it may have formed through processes similar to those on Earth.

Venus is sometimes called Earth's sister planet because of their shared physical, geological, and atmospheric features. Scientists have discovered something new about Venus's geology that reminds us of the similarities between the two planets. To understand what the researchers found, we need to look deep inside both planets.

There are several reasons why this pair of planets is sometimes called twins. They have several characteristics in common:

They are neighbors in the inner solar system.
They are both rocky.
They are approximately the same size and weight.
Both have few craters, indicating a young surface.
They have an atmosphere and thick clouds.
They have geological similarities and surface features such as volcanoes, mountains, plateaus and plains.

A new study published in the journal Nature Geoscience addresses the last item on that list. It is titled,Ishtar Terra plateau on Venus, raised by craton-like formation mechanisms” Lead author is Fabio Capitanio, Associate Professor in the School of Earth, Atmosphere and Environment at Monash University.

Ishtar Land is one of three large highland regions on Venus. Its relief includes mountains, plains and plateaus. Ishtar Land contains the Maxwell Mountains mountain range, its height is about 11 km, while the height of Everest is 8.8 km.

Ishtar Land has a very complex topography and appears to be heavily deformed, indicating that Venus has experienced significant geological activity in the past.

A view of Venus centered on its north pole. Ishtar Land is the red area just below the center of the image. The white area is the Maxwell Mountains, and the leftmost red band is the Lakshmi Plateau.

Ishtar Land also contains the Lakshmi Plateau, a two-million-square-kilometer plateau about four kilometers high, surrounded by highly deformed terrain. It consists of smooth lava flows and includes two large shield volcanoes. Diameter paters Colette is about 130 km across, and the Sakahawei Pateras are about 200 km across and 1-2 km deep. Although Venus is currently tectonically inactive, scientists believe that ancient tectonic activity is responsible for the region's wild topography.

The link contains an interactive 3D map.

A new study published in the journal Nature Geoscience looks at a special part of geology called the study of cratonsCratons are ancient geological platforms of the Earth's continents. They are stable parts of the Earth's lithosphere that are usually found at the center of the planet's continental plates. Cratons have experienced an extensive history of continental breakup and merging. They are typically composed of extremely strong basement rocks and have deep roots that can extend hundreds of kilometers into the planet's mantle.

Some cratons formed in the Precambrian era, more than 2.5 billion years ago. Others may be even older, dating back to the early period of Earth's existence, the Hadean and Archean eons.

In the new paper, Capitanio and his co-authors used data from NASA's Magellan spacecraft and high-performance computer modeling to delve deeper into how Ishtar Terra formed. They found that Ishtar Terra may have formed in a similar way to Earth's cratons.

On Earth, plateaus and mountain belts like Ishtar Land are likely the result of continental plate collisions. Ishtar Land is similar to the Tibetan Plateau, and continental collisions are the main cause of its formation. Something else must be behind Ishtar Land and other terraces on Venus, since the planet lacks plate tectonics. But Ishtar Land does have something in common with Earth. It has a thick crust similar to Earth's cratons.

This suggests that the planets share or have shared processes. Ishtar Land and other regions of Venus may have formed from the planet's hot interior. There are several competing explanations for the formation of Earth's cratons, but one is the molten plume model. It posits that rising plumes of molten rock come from deep within the Earth's mantle and form thick layers with cratons sitting on top.

“This study challenges our understanding of how planets evolve,” says lead author Capitanio. “We didn’t expect Venus, with its scorching 460°C surface temperature and lack of plate tectonics, to have such complex geology.”

Although Venus does not have plate tectonics, it does have a hot lithosphere. The planet's surface temperature is about 460°C. The heat extends into the lithosphere, which is hotter than Earth's due to Venus' greenhouse effect. The surface simply cannot remove heat the way Earth can. This intense heat means that Venus' lithosphere is likely thinner than Earth's. While Earth's lithosphere can be up to 200 km thick, or more, Venus' lithosphere is only 50-100 km thick. Because it is so much thinner, it is also weaker.

“Venus’s hot lithosphere may make it a good analogue of the early Earth and facilitate the same types of continent-forming processes that occurred on Earth,” the researchers wrote in a briefing in Nature. “We focused on Ishtar Terra, the widest of the plateaus, for which we found that the topography, crustal thickness, and gravity signals are consistent with our simulations when the modeled lithosphere is about 10 to 50 times weaker than Earth’s.”

This figure from the study compares observational data (a, c, e) and model results (b, d, f). The columns are topography, crustal thickness, and gravity anomaly at 194 million years. “The structures emerging in this model provide topography, gravity, and crustal thickness remarkably comparable to the plateaus of Venus,” the researchers explain.

The thin lithosphere favors “the formation of thick magmatic crust on top of deep residual depleted mantle,” the authors write in their study.

“This discovery opens up a fascinating new window into Venus and its potential connections to early Earth,” Capitanio said. “The features we found on Venus are strikingly similar to Earth’s early continents, suggesting that Venus’s past dynamics may have been more Earth-like than previously thought.”

The study shows that despite their differences, rocky planets can share common mechanisms. Finding such cratons or craton-associated mechanisms on another planet could help scientists understand Earth. “By studying such features on Venus, we hope to unlock secrets about Earth’s early history,” says Associate Professor Capitanio.

Venus is like the solar system's plan B. If life couldn't start on Earth, maybe it could start on Venus.” There is evidence that Venus once had liquid water and was in the habitable zone, although this is not certain. In any case, if life exists on Earth, then Venus

Venus is like the solar system's plan B. If life couldn't survive on Earth, maybe it could survive on Venus. There is evidence that Venus once had liquid water and was in the habitable zone, although this is not certain. In any case, if there is life on Earth, Venus is too hot.

Earth's ancient cratons are part of its history. On our planet, geology, life, and atmosphere are closely linked. Understanding what Earth and Venus have in common and how they differ will allow researchers to learn more about Earth's trajectory as a living planet.

Future missions to Venus are already in development, and they should provide even more explanations for the different outcomes of the sister planets.

“Our research paves the way for future missions to Venus, such as DAVINCI, VERITAS and EnVision,” Capitanio said. “These missions will provide additional information about the geological history of Venus and its relationship with Earth.”