Astronomie - Dozens of active volcano sites spotted on Venus for the first time



Sapas Mons is a large volcano on Venus


Several dozen active volcanic sites have been identified on Venus for the first time. The discovery may aid future missions to the planet and add to our understanding of why there is life on Earth, but not Venus.

Anna Gülcher at the Swiss Federal Institute of Technology in Zurich, Switzerland, and her colleagues created high-resolution simulations of how volcanic sites on Venus could form, based on our understanding of the planet’s interior using data from the European Space Agency’s Venus Express mission, which ended in 2014.  They then looked at infrared images from NASA’s Magellan mission to Venus in the early 1990s to see if the images matched their simulations.

“People have suggested that Venus is volcanically active before,” says Gülcher, meaning it has volcanoes that have erupted in the last million years or so. “What we have done that is new is to map out these regions and correlate them to these specific sites.”

The simulations allowed the researchers to identify what features a currently active volcanic site would possess. Most notably, they looked for a trench around a site’s outer ring and a bulge on the trench’s edge.

Looking at the Magellan images, they found that at least 37 volcanic sites had these features, suggesting they are active. The volcanic sites, called coronae, are much larger than Earth’s volcanoes. The average corona that the researchers looked at had a diameter of 300 kilometres. Mauna Loa in Hawaii, the largest active volcano on Earth, is only 120 kilometres wide.

The researchers also found that most of these sites were in a belt around the planet, which they have dubbed the Ring of Fire. Gülcher hopes that future missions to Venus will focus on this region in order to learn more about the planet’s geology.

“Based on size, chemistry and position in the solar system, Venus is the most Earth-like planet ever observed,” says Sami Mikhail at the University of St Andrews, UK. “Understanding whether or not the planet is volcanically active today is an integral piece of the puzzle to revealing why Earth is the definition of habitable, and Venus is a barren, hot and hellish wasteland.” 

Quelle: NewScientist

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