Signs of geological activity found on Venus - BBC News
Scientists have found evidence parts of Venus's surface move around like pieces of continent on Earth.And while this activity is probably not driven by plate tectonics, as on Earth, it could be a "cousin" of that process."We've identified a previously unrecognised pattern of tectonic deformation on Venus, one that is driven by interior motion just like on Earth," said lead author Paul Byrne, associate professor of planetary science at North Carolina State University.Dr Byrne, Dr Richard Ghail, from Royal Holloway, University of London, Prof Sean Solomon, from Columbia University, in New York, and colleagues detected signs blocks of rocky crust in Venus's lowlands region had rotated and moved laterally relative to one another.They compare the apparently relatively recent activity to the way fragments of pack ice jostle around in the sea in Earth's polar regions.The blocks - 100-1,000km (620 miles) long - also resemble the Earth's crust in:.Traditionally, Venus's lithosphere - its rocky outer layer - was thought to be in one continuous piece, in contrast to the Earth's, which is broken up into a mosaic of mobile tectonic plates.But the findings, published in the journal PNAS, suggest Venus's lithosphere actually has some degree of mobility - though nowhere near as much as Earth's.The results of computer models show molten rock - magma - roiling beneath the crust could produce the strain, fracturing and distortion seen in Magellan images of the surface.So Venus's tectonic activity might resemble that on early Earth, during the Archean Eon, between four billion and 2.5 billion years ago, when the heat flow within the planet was higher and the lithosphere thinner.