New discovery challenges everything we thought about Earth's twin
A recent study led by geoscientist Fabio Capitanio of Monash University in Australia, has revealed that the 'continents' of Venus, known as tesserae, might have been formed through processes similar to those that created Earth's earliest continents billions of years ago. This discovery challenges existing theories about planetary evolution. "We did not expect Venus, with its scorching 460°C surface temperature and lack of plate tectonics, to possess such complex geological features," said Capitanio.
Venus's tesserae show tectonic features
Unlike Earth, Venus does not have tectonic plates, a characteristic believed to significantly contribute to the differences between the two planets. However, the oldest parts of Venus's surface, the tesserae, display tectonic features. The formation of these features has been a mystery until now. Capitanio and his team used data from NASA's Magellan spacecraft that mapped the surface of Venus in detail between 1989 and 1994.
Study focused on Ishtar Terra, Venus's largest plateau
The research team concentrated on a tesserae region known as the Ishtar Terra, Venus's largest plateau. Using computer simulations and data from the Magellan spacecraft, they investigated how this region formed billions of years ago when the Solar System was still in its infancy. The findings suggest that the tesserae may have formed like Earth's cratons - regions where rock is older, denser, and stronger.
Tesserae's formation process mirrors Earth's cratons
The study indicates that the tesserae's formation process mirrors that of Earth's cratons, which are believed to have surged upwards from within Earth's molten interior and hardened into the planetary crust. "The features we found on Venus are strikingly similar to Earth's early continents," Capitanio explains. This discovery implies that Earth and Venus diverged along their separate crustal journeys after the process of craton formation but before the development of plate tectonics.
Discovery could provide insights into habitability on rocky planets
The timing of this divergence could offer crucial insights into how habitability is established and maintained on rocky planets like Earth. "By studying similar features on Venus, we hope to unlock the secrets of Earth's early history," Capitanio says. The research also suggests that Venus may have transitioned from limited tectonic movement early in its history to the stagnant lid model that exists today.
Computer modeling reveals Venus's geological transition
The team's computer modeling, combined with data from the Magellan spacecraft, demonstrated how plateaus could form through a process where planet's surface thins and melts due to its low strength. This causes elevated areas as molten rock rises, leading to cooling and formation of high plains surrounded by folded belts over time. Capitanio concluded by highlighting future missions to Venus like DAVINCI+, VERITAS, and EnVision that aim to provide further insights into Venus's geological history and its connection to Earth.
