A team at NASA claims that observations, from the European Space Agency’s Venus Express mission and the US space agency’s Magellan spacecraft, have revealed that volcanoes on the planet appeared to erupt between a few hundred years to 2.5 million years ago.
This suggests the planet may still be geologically active, making Venus one of the few worlds in our solar system that has been volcanically active within the last 3 million years, say the astronomers.
In their study, the astronomers analysed compositional differences compared to the surrounding landscape in at least three volcanic regions. Relatively young lava flows have been identified by the way they emit infrared radiation.
These observations suggest Venus is still capable of volcanic eruptions, they say.
“The geological history of Venus has long been a mystery. Previous spacecraft gave hints of volcanic activity, but we didn’t know how long ago that occurred.
Now we have strong evidence right at the surface for recent eruptions,” said lead author Sue Smrekar of NASA’s Jet Propulsion Lab in Pasadena, California.
In fact, the volcanic provinces, or hotspots, on which the NASA team focused are geologically similar to Hawaii.
Something is smoothing Venus’ surface, because the planet has only about 1,000 craters, a relatively small amount compared to other bodies in our solar system, say astronomers who think it may be the result of volcanic activity.
The Venus Express results suggest a gradual sequence of smaller volcanic eruptions as opposed to a cataclysmic volcanic episode that resurfaces the entire planet with lava.
The NASA team also discovered that several volcanic features in the regions it studied show evidence of minerals found in recent lava flows. These mineral processes correspond to the youngest volcanic flows in each region, giving them the additional support for the idea that they formed during recent volcanic activity.
On Earth, lava flows react rapidly with oxygen and other elements in the atmosphere when they erupt to the surface. On Venus, the process is similar, although it is more intense and changes the outer layer more substantially.
Venus is called Earth’s sister planet because of similarities in size, mass, density and volume. Astronomers deduce that both planets shared a common origin, forming at the same time about 4.5 billion years ago. Venus also is the planet on which the runaway greenhouse effect was discovered.