The discovery was announced at a major conference of planetary researchers in Texas and will be published this week in a weekly magazine Sciences. This discovery provides further insight into the role played by volcanoes on a planet without plate tectonics and continental drift, the geological processes responsible for much of the volcanic activity on Earth.
Robert Herrick of the University of Alaska and Scott Hensley of NASA’s Jet Propulsion Laboratory loved providing detailed images of the large ash clouds and spectacular lava fountains. However, it is not seen: the surface of Venus is obscured by a permanently closed cloud cover. Instead, they found significant landscape changes in ancient radar measurements, which are almost certainly due to volcanic activity. After Earth and Jupiter’s moon Io, Venus is now the third celestial body in the solar system to experience active rocky volcanism.
radar
More than thirty years ago, the surface of Venus was mapped by the American space probe Magellan using radar. In addition, many regions of the planet have been measured twice, with an interval of eight months. Herrick and Hensley have now re-examined the old Magellan notes, looking for striking differences.
On the north side of Maat Mons, a five-kilometer-high shield volcano, they discovered a relatively small crater more than a kilometer and a half in diameter that is roughly circular in the first “radar image”. In the second image, the crater is much larger and irregularly shaped. Moreover, it seems less deep, as if it was filled with lava. A little further north, a new lava field of about seventy square kilometers may have formed as well.
According to the researchers, all of this indicates that Ma’at Mons is still active, just like the large shield volcano Mauna Loa in Hawaii. It certainly looks like that, says volcanologist Bernd Andweg of the Free University of Amsterdam. “It is very complex to explain such a dramatic change in landscape in such a short time in any other way, although the researchers themselves are still a bit cautious.”
on the shelf
Sebastian de Wit, a planetary researcher at TU Delft, was also surprised by the finding. “It’s good to see that new discoveries are still being made based on older observational data,” he says. “Especially because there is still a lot of material on the shelf.”
De Vet is looking forward to new space flights to Venus with interest. The European space probe Envision will study the planet in greater detail in the 2030s, again using radar. This was more than forty years after the radar measurements of Magellan.
If the landscape of Venus can undergo such a radical transformation within eight months, then the effects of volcanic activity should be quite evident after forty years. De Wit: “If this discovery is corroborated by observations from future space missions, of course that would be great.”
