A team of American planetologists reported the discovery of traces of two huge craters on the surface of Venus. They were formed at an early stage of the planet’s life about 3.5 billion years ago.
One of the peculiarities of Venus is that no craters larger than 300 km in diameter have been found on it. Scientists associate this with the fact that in the relatively recent past (600 million years ago), almost the entire surface was flooded by lava flows, which hid the traces of previous impacts.
However, perhaps some traces of the giant collisions of the past still managed to survive to this day. A team of researchers looked at an area of the planet called the Haasttse-baad Tessera. It is a concentric multicircular formation with a diameter of 1,500 kilometers. Something similar has been found on Callisto before. There, the ring structures resulted from the displacement of water from beneath the surface by large asteroid impacts, which deformed the crust.
In the course of simulations, the scientists concluded that the Haasttse-baad Tessera may have arisen in a similar way. This is possible if the surface of early Venus was a thin hard shell over a molten mass. In this case, the fall of a large object would result in its piercing, after which molten material beneath the surface would be pushed outward, causing deformation of the crust and the formation of concentric rings.
Additional analysis also showed that some of the rings on the surface of the Tessera are displaced. This may indicate that it was formed as a result of the almost simultaneous fall of two objects with a diameter of about 75 km each in the same place. The first impact formed a sea of lava that shaped the terrain of the Tessera. Then a second impact collapsed the lava sea, forming concentric rings. Scientists estimate that this event could have occurred about 3.5 billion years ago.
We previously told you that Venus’ geologic history may be more Earth-like than thought.
Provided by Phys.org
