Is Venus volcanically active? A study offers a new approach to resolving the controversy

 

Of all the planets, Venus has the most volcanoes. Much of the planet is covered by volcanic deposits that are less than 300 million years old. Volcanic activity has played a pivotal role in its history.

Although the exact timeline of Venus's volcanic past is still being debated, some data suggests that the planet may still have active volcanoes, but the evidence is still inconclusive.

So far, researchers have had difficulty determining whether there are active volcanoes on Venus for several reasons. The planet's atmosphere is corrosive, characterized by high pressures and temperatures above 450 degrees Celsius (842 degrees Fahrenheit). This makes it unfit for the types of spacecraft that can last for years on Mars or the Moon.

Meanwhile, thick sulfuric acid clouds limit visual observations of the planet's surface. So the researchers turned to other distant measurements, including radar data from NASA's Magellan spacecraft.

This helped researchers from the Italian University of Milan to announce a new approach that could help solve the mysteries of volcanic activity on Venus, during a study published in the Journal of Geophysical Research.

This approach combines geological mapping of cooling lava flows from previous eruptions with additional radar data from the Magellan mission. Specifically, it is based on measurements of the planet's radar emission - a measure of how its surface interacts with and emits microwave radiation.

Different parts of the surface of Venus have different levels of emissivity that correspond to different properties of the rocks, providing clues to their formation.

In particular, recent research indicates that radar emission can be used to determine the degree of chemical weathering to which lava flows are subjected after they erupt and come into contact with the harsh atmosphere. Such weathering occurs over weeks or months, so emissivity can help identify new lava flows.

The authors combined radar emission measurements with geological maps to compare three volcanoes to Venus: Maat Mons, Uza Mons and Sabas Mons.

The results indicate that some of the pyroclastic flows in "Maat Mons" may be relatively small.