Rosaly Lopes has spent five years analyzing a stirring landscape that kept erupting. Using data from an orbiting satellite, the researcher selected outbursts throughout the hot surface, ultimately detecting 71 active volcanoes that no one had identified before.
“People used to joke with me, ‘Oh, you found another active volcano!'” Lopes said. “‘You’re going to be in the Guinness World Book of Records.'”
Lopes has actually ended in the 2006 edition of the Guinness World Records as the researcher who discovered the most active volcanoes anywhere. However, none of those eruptions took place on Earth but were on a moon of Jupiter, known as Io.
Io is the Ideal Candidate for Our Understanding of Such Worlds
Now, Io is recognized as the most volcanically active place in the Solar System. Other volcanic places are spread throughout planets and moons in our vicinity as well, and most likely a myriad of more in other Solar Systems across the Universe.
Not long ago, NASA announced it would fund suggestions for four new robotic expeditions aimed at these types of worlds: Io, Venus, and Triton, a moon of Neptune. Earth was recognized for the most volcanic place in the Solar System until recently. Generally, volcanic activity suggests that a world is cooling off. After planets and moons take shape, they can experience billions of years of heat emission from their inner cores through cracks in the surface.
“Volcanism is like a window into the interior of the planet,” says Sue Smrekar, an astronomer at NASA’s Jet Propulsion Laboratory who is conducting one of the suggested expeditions.
Back in the 1970s, researchers foresaw that the Voyager mission would find moons like our own. The moons attached to Jupiter, for instance, are approximately the size of our Moon, or smaller, so it was only logical that they could be cold, as well as abounding in craters.
“It was very hard for people to accept that such a small moon-like Io could still have active volcanism because Io should have cooled a long time ago,” Lopes said.
Now, after 40 years, planetary scientists have started focusing on finding eruptions across the Solar System.
Venus Could Experience Volcanic Activity Again
Io experiences a phenomenon known as tidal heating, which warms the moon’s inner part, melting rock into lava. As the cosmic object expands and shrinks throughout its 42-hour orbit, fissures appear on its surface, and the lava breaks free.
“It’s changing the shape of the whole planet,” says Alfred McEwen, a planetary geologist at the University of Arizona who is behind the mission concept of Io.
Numerous exoplanets discovered so far rotate close enough to their stars to encounter similar tidal heating, which makes Io an ideal example for understanding places beyond our vicinity, McEwen said.
Closer to us, there’s Venus, whose entire surface bears the traces of volcanoes rolling through a period of eons.
“We see huge fields of small volcanoes in places on Venus that remind us of the little guys we see in Iceland,” says James Garvin, the chief scientist at NASA’s Goddard Space Flight Center and the lead researcher on one of the Venus expeditions.
The planet’s volcanoes are believed to have to drain a long time ago, but researchers have found proof that some activity might be underway as an infrared camera on a European spacecraft noticed spots on the surface suddenly heating up and cooling down again.