Venus still geologically active

Washington, Apr 9 (ANI): Venus is alive - geologically speaking, say researchers. t was ESA's Venus Express that clearly indicated that Venus is geologically active.

Relatively young lava flows have been identified by the way they emit infrared radiation. The finding suggests the planet remains capable of volcanic eruptions.

"Now we have strong evidence right at the surface for recent eruptions," says Sue Smrekar, a scientist at NASA's Jet Propulsion Laboratory in California.

That strong evidence comes in the form of compositional differences compared to the surrounding landscape in three volcanic regions. The data were collected by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on ESA's Venus Express spacecraft, which has been orbiting the planet since April 2006.

VIRTIS records the brightness of surface rocks, providing an estimate of 'emissivity'. In 2008, Jorn Helbert and Nils Muller, Institute of Planetary Research, German Aerospace Center, Berlin and co-authors on this new work, published a map of the variation of infrared emissivity across the southern hemisphere of Venus.

Dr Smrekar and her colleagues targeted three regions that geologically resemble Hawaii, well known for its active volcanism. They show that the regions on Venus have higher emissivities than their surroundings, indicating different compositions.

On Earth, lava flows react rapidly with oxygen and other elements in the atmosphere, changing their composition. On Venus, the process should be similar, though more intense because of the hotter, denser atmosphere, chiefly of carbon dioxide.

The researchers interpret the fact that the lava flows appear to have different compositions from their surroundings as being evidence of a lack of surface weathering, indicating that the flows erupted relatively recently. They estimate that the flows are possibly as geologically recent as 2 500 000 years - and likely much less, possibly even currently active.

"This is a significant result," says Hakan Svedhem, ESA Venus Express Project Scientist. (ANI)