Venus, Earth's nearest neighbour, may be volcanically active, say scientists who have found strong evidence of active lava flows on the planet.
Analysing data from the European Space Agency's Venus Express mission, the scientists found transient spikes in temperature at several spots on the planet's surface.
The hotspots, which were found to flash and fade over the course of just a few days, appear to be generated by active flows of lava on the surface, researchers said.
"We were able to show strong evidence that Venus is volcanically, and thus internally, active today," said co-author James W Head, a geologist at Brown University.
This is a major finding that can help us better understand the evolution of our own planet, Head said.
The hotspots turned up in the thermal imaging taken by the Venus Express spacecraft's Venus Monitoring Camera. The data showed spikes in temperature of several hundred degrees Fahrenheit in spots ranging in size from 1 square kilometre to over 200 kilometres.
The spots were clustered in a large rift zone called Ganiki Chasma. Rift zones are formed by stretching of the crust by internal forces and hot magma that rises toward the surface.
Head and Russian colleague Mikhail Ivanov had previously mapped the region as part of a global geologic map of Venus generated from the Soviet Venera missions in the 1980s and US Magellan mission in the 1990s.
The mapping work had shown that Ganiki Chasma was quite young, geologically speaking, but just how young wasn't clear until now.
"We knew that Ganiki Chasma was the result of volcanism that had occurred fairly recently in geological terms, but we didn't know if it formed yesterday or was a billion years old," Head said.
"The active anomalies detected by Venus Express fall exactly where we had mapped these relatively young deposits and suggest ongoing activity," Head said.
The latest finding is consistent with other data from Venus Express that have hinted at very recent volcanic activity.
The observation of hotspots by Venus Express, combined with the geologic mapping from Venera and Magellan, make a strong case for a volcanically active Venus, Head said.
The research is published in Geophysical Research Letters.
