The process by which Earth loses heat is generally understood, but this is not the case for our neighboring planet, Venus. A new study published in the journal Nature Geoscience investigated how Venus cools and discovered that the thin portions of the planet’s uppermost layer may contain the solution. Researchers consulted 30-year-old data from NASA’s Magellan spacecraft for this analysis.
Venus is known as Earth’s twin because it is rocky, roughly the same size, and has similar rock chemistry to our planet. One would think that Venus and Earth would lose internal heat to space at roughly the same rate, but this is not the case. The most recent analysis paints a more complete picture of what is going on on our nearest neighbor planet.
How does the Earth lose heat?
Earth has a hot core that heats the surrounding mantle, which then transfers the heat to the lithosphere, Earth’s stiff outer rocky layer. The heat is then expelled into space, which helps to cool the mantle’s highest portion. This heat-transfer process in the mantle drives tectonic processes on the surface and keeps the mobile plates moving.
Venus has no tectonic plates
Venus, on the other hand, lacks tectonic plates. As a result, the mechanisms that shape the planet’s surface and how it loses heat are not fully understood. The coronae, which are quasi-circular geological landforms on Venus, were studied by researchers.
Researchers examined the quasi-circular geological landforms known as coronae on Venus based on observations made by the Magellan mission in the early 1990s. The scientists conducted fresh measurements of coronae visible in Magellan pictures for the study and concluded that coronae are more likely to be found where Venus’ lithosphere is thinnest and most active.
Our understanding of Venus’s lithosphere is changing: NASA
“For so long we’ve been locked into this idea that Venus’ lithosphere is stagnant and thick, but our view is now evolving,” said Suzanne Smrekar, a senior research scientist at NASA’s Jet Propulsion Laboratory in Southern California.
Researchers concentrated on 65 previously unstudied coronae
The researchers concentrated on 65 previously unstudied coronae that can span hundreds of kilometers. They calculated the thickness of the surrounding lithosphere by measuring the depth of the trenches and ridges around each corona. The researchers discovered that the ridges were closer together in locations where the lithosphere was more flexible, or elastic.
The average thickness of the lithosphere around each corona was roughly 11 kilometers
Using computer modeling, the scientists concluded that the average thickness of the lithosphere around each corona is roughly 11 kilometers, which is substantially thinner than prior estimates.
Furthermore, these places were discovered to have an estimated heat flux that is larger than the average for the Earth, implying that the coronae are geologically active.
Significant heat escapes through thin lithosphere regions.
“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 Smrekar.
Venus is covered with old craters
Now comes the exciting part. Scientists count the number of visible impact craters to determine the age of a celestial body’s surface. These craters are erased by geological processes such as continental plate subduction or are buried by molten rock from volcanoes on tectonically active worlds such as Earth. Venus, due to its lack of tectonic activity, should be riddled with ancient craters.
According to scientists, the surface of Venus is quite new
Scientists have established that the surface of Venus is relatively new by calculating the number of Venusian craters. The latest research suggests that Venus’s young appearance may be due to volcanic activity. The most recent research backs up this fact.
“Venus provides a window into the past”
“What’s interesting is that Venus provides a window into the past to help us better understand how Earth may have looked over 2.5 billion years ago. It’s in a state that is predicted to occur before a planet forms tectonic plates,” said Smrekar. NASA is planning a mission, called VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, And Spectroscopy) to probe the planet.