Volcanoes on Venus are sign planetary neighbor is active, scientists say

Hidden beneath a thick atmosphere, volcanoes may still be erupting on the surface of Venus, a new study finds.

The findings, described in the journal Geophysical Review Letters, reveal that our nearest planetary neighbor could be far more active than previously thought.

Scientists often look to our neighboring planets to learn more about Earth’s past. Mars, for instance, is thought to have had water and perhaps an atmosphere thick enough to support life; tiny, sun-scorched Mercury still has a liquid outer core that powers a magnetic field, rather like Earth’s.

Venus, our closest planetary companion, could provide insights of its own, but it is shrouded in thick clouds of sulfuric acid that block out visible light.

And that’s too bad, said study co-author James Head, a planetary geoscientist at Brown University, because in many ways it would be the best planet to study to learn more about Earth and its history.

“Venus — in terms of its size, its density, position in the solar system — is literally the most Earth-like planet,” Head said. “And I think that if we could see what was going on in the formative years of Earth, that would be really incredible.”

Russian landers in the 1970s and ’80s noted some familiar terrain, including — James Head, planetary geoscientist at Brown University plateaus and features that resembled mountain belts. But they revealed surprisingly few craters.

The terrain indicated that the surface had been active, undergoing the kind of geophysical churn seen on Earth. Venus, like Mars, had clearly had volcanic activity in the distant past — but could it be continuing today?

“People were thinking, ‘Well, is it like the Earth, which is very active, or is it like the moon and Mars, which are like a bunch of craters?’ ” Head said.

Data from NASA’s Magellan spacecraft, which entered Venusian orbit in1990, seemed to say that Venus was geophysically dead. But if it had been inactive for a very long time, then it should be heavily cratered.

To get at that question, the scientists turned to the European Space Agency’s Venus Express spacecraft, to look for bright spots that signaled local lava flows.

Sure enough, the scientists found bright spots that indicate temperature spikes caused by flowing lava, a sign that Venus is still active.

“People were thinking, ‘Well, is it like the Earth …?’ ”

amina.khan@tribpub.com