This extra energy superheated Venus' interior, supporting billions of years' worth of volcanism, the new research found. "Higher-impact velocities melt more silicate, melting as much as 82% of Venus' mantle," said study co-author Raluca Rufu of SwRI in a statement. Marchi's team compared the impact histories of Earth and Venus, and found that Venus was hammered by more energetic impacts.
And so a team of planetary scientists, led by Simone Marchi of the Southwest Research Institute (SwRI) in San Antonio, Texas, have found another possible explanation.Įarly in the history of the solar system, the inner planets were being pelted by asteroids and comets. One leading theory had been that Venus endures bouts of cataclysmic volcanism every 500 million years or so as heat builds up beneath a thick, stagnant crust, but the mechanism to allow this had always been vaguely described. On Earth, plate tectonics are the main driver of volcanism, but since Venus lacks plate tectonics, what drives its volcanic activity has been something of a mystery. Over geological timescales, lava can flood the planet's surface, filling in craters and creating a more youthful appearance than Venus' true age of 4.5 billion years. Most of these are volcanic vents from which lava seeps out rather than explosive volcanoes from mountaintop calderas, and earlier this year scientists made the first discovery of active volcanism on the Venusian surface.
What Venus does have is volcanoes, and a lot of them - more than 80,000, in fact.
0 kommentar(er)
