On Earth, the planet's core heats the surrounding mantle which then conveys heat to the outer layer or lithosphere, where it then radiates out into space, causing the Earth's mantle to cool, driving the movement of tectonic plates, the study published in the Nature Geoscience journal states.
"Earth and Venus are rocky planets of about the same size and rock chemistry, so they should be losing their internal heat to space at about the same rate," NASA said in a press release summarizing the findings.
"How Earth loses its heat is well known, but Venus' heat flow mechanism has been a mystery."
Venus does not have tectonic plates, and was once believed to have a thick lithosphere. New research suggests parts of Venus' lithosphere are much thinner than previously believed, and that geological activity in those areas bleeds heat from the planet.
Scientists at the Jet Propulsion Laboratory based their findings on a reexamination of images of Venus' surface taken by the Magellan spacecraft during the early 1990s. Scientists examined 65 geological structures on the surface, known as Coronae.
Coronae are approximately circular formations, that can span hundreds of miles, that are believed to be formed by geological activity on Venus.
"To calculate the thickness of the lithosphere surrounding them, they measured the depth of the trenches and ridges around each corona. What they found is that ridges are spaced more closely together in areas where the lithosphere is more flexible or elastic," NASA said.
"Making new measurements of the coronae visible in the Magellan images, the researchers concluded that coronae tend to be located where the planet's lithosphere is at its thinnest and most active."
Researchers used a computer model to determine that the lithosphere near the coronae is approximately 7 miles thick, which is much thinner than previously thought.
"While Venus doesn't have Earth-style tectonics, these regions of thin lithosphere appear to be allowing significant amounts of heat to escape, similar to areas where new tectonic plates form on Earth's seafloor," said senior Jet Propulsion Laboratory research scientist and study leader, Suzanne Smrekar.
Related Links
Venus Express News and Venusian Science
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