Researchers combing decades-old spacecraft data have found clear signs of recent volcanic activity on Venus. The findings, published in the journal Sciencenot only reveal that the planet’s surface is currently a turbulent place, but also provide insight into its geological past and future.
Either way, Venus is a hellscape: crushing pressure, a toxic atmosphere, and surface temperatures high enough to melt lead. It’s like a scene taken straight from Dante’s Inferno.
It’s “my favorite planet,” says Robert Herrick, a planetary scientist at the University of Alaska Fairbanks.
For all its animosity, Venus – our closest planetary neighbor – is actually quite similar to Earth. So much so that Herrick calls it our “real brother” in the solar system. The resemblance is “driven by what’s going on in their interiors,” he says.
“Aside from Earth,” says Herrick, “it’s the only planet with true mountain ranges and a huge variety of volcanic features.” These features include lava fields, channels carved by molten rock, and hundreds if not thousands of volcanoes.
So it’s clear that Venus is volcanically active, which gives it a youthful appearance (in geological terms). But it is not clear exactly how active.
“That could still mean that the time between eruptions could be months, years or tens of thousands of years,” says Herrick.
So he tried to narrow that time window by looking for evidence of recent volcanic activity. He turned to surface radar images collected by the Magellan spacecraft in the early 1990s.
“Thirty years ago,” he says, “it just wasn’t feasible to pan around and zoom in and out and flip back and forth between different global mosaics.” But computer hardware and software have improved considerably, so Herrick was able to bend over the images.
“It’s a needle in a haystack with no guarantee that there is a needle,” he admits.
Herrick focused his search around the tallest volcano on Venus called Maat Mons, named after the ancient Egyptian goddess of truth and justice. And after a few months of looking around an area the size of Australia, he found something.
It can be clearly seen in two side-by-side black and white photos taken eight months apart at the same spot on the north side of the volcano. Each is about 15 or 20 miles wide. Herrick points to a pockmarked bottom. It is a vent – the area where a volcano erupts and discharges its lava, ash and rock. But the shape of that vent differs between the two images.
“The outline has changed and the thing has actually gotten bigger and also looks more shallow,” he says. That is, within just eight months of 1991 (the same year that President George H.W. Bush declared victory over Iraq and Clarence Thomas was confirmed as Supreme Court justice), Herrick speculates that the volcano erupted, forming a lava lake in the vent.
“Of course I could have been very lucky and seen the only thing that’s happened on Venus in the last million years,” says Herrick. “But I think the reasonable interpretation suggests that Venus is relatively Earth-like in the frequency of volcanic eruptions,” similar to that of Hawaii and Iceland.
Unlike Earth, Venus has no plate tectonics. So researchers have been trying to figure out how the planet has evolved geologically over the past four and a half billion years and where it might be headed. Herrick and his colleague Scott Hensley hope their findings will help.
“It’s nice to have a visual confirmation of the volcanic activity on Venus,” said Clara Sousa-Silva, a quantum astrochemist at Bard College who was not involved in the study. “But given that this was something we had speculated, it’s not shocking that this article comes out.”
Still, Sousa-Silva says this confirmation of activity on the surface of Venus helps us better understand what to expect on the surface of Venus. atmosphere.
“A planet with a lot of volcanic activity,” she says, “has access to these extreme pressures and temperatures below the surface that can produce molecules that are really unusual and otherwise very hard to make.”
Much of NASA’s (and the public’s) recent attention has been drawn to Mars; the space agency has landed five rovers on the red planet’s dusty surface since 1997.
But Herrick says Earth’s resemblance to Mars is somewhat superficial and pretty much limited to surface features like blowing sand, desert landscapes, and signs of what may have once been lakes and rivers.
However, the interesting wind has turned. “Maybe it will cycle back like whistleblowers,” says Herrick with a chuckle.
That’s because NASA currently has two missions to Venus in the works, which will now be informed by Herrick’s findings. “We don’t just think it’s an active planet,” he says. “We know it’s an active planet — right now.”
Herrick is working with NASA to develop an instrument for those upcoming missions to monitor volcanic activity on Venus. He’s pretty confident now that the seismometer will register something once it’s deployed – as long as it can survive the infernal planet long enough to take its readings.