Venus, the hottest planet in the solar system, continues to reveal secrets about its extreme geology. A study published in Nature Communications has discovered that its crust is much thinner than expected, challenging traditional theories about its evolution.
Unlike Earth, Venus lacks tectonic plates, so scientists believed that its outermost layer should thicken over time. However, the new study proposes an alternative process, in which the base of the crust breaks away or melts, affecting its internal composition.
How does Venus’ geology work?
The Earth’s crust is composed of massive plates that slide, collide, and generate faults, in a process known as plate tectonics.
When two plates collide, the lighter one slides over the denser one, pushing it towards the Earth’s mantle, in a phenomenon called subduction. This mechanism controls the thickness of the crust and contributes to volcanic activity.
But on Venus, where the crust is a single piece, this process does not exist, making its evolution completely different.
A thinner crust than anticipated
The study, led by the Deputy Director of the Astromaterials Research and Exploration Division at NASA, Justin Filiberto, used models to determine the thickness of Venus’ crust.
The results were surprising:
- 40 km average thickness.
- Maximum of 65 km, much less than expected.
“It is surprisingly thin given the planet’s conditions,” commented Filiberto.
According to the models, when the crust thickens, its base becomes so dense that it breaks away and incorporates into the mantle or melts, affecting the planet’s internal dynamics.
Metamorphism on Venus: the key factor
Although Venus lacks tectonic plates, its crust does undergo a metamorphic process, similar to Earth’s.
This phenomenon can return water and elements to the planet’s interior, in addition to influencing volcanic activity, a crucial aspect in Venus’ evolution.
Why is this finding important?
The study represents a significant advancement in understanding Venus’ geological processes, as it:
- Explains why its crust has not thickened over time.
- Provides data on the possible interaction between the crust and the mantle.
- Suggests new connections between Venus’ geology and volcanic activity.
These results could be key for future planetary explorations and for understanding how worlds without tectonic plates evolve.
