This five-frame sequence of images from NASA’s New Horizons mission captures the giant plume from Io’s Tvashtar volcano. Credit: NASA
Jupiter’s moon Io is blowing up right now. At least, parts of it are erupting. Scientists have now imaged ongoing volcanic eruptions on the distant moon from observatories here on Earth.
At an International astronomy conference held in Pasadena, scientists from the University of California, Berkeley revealed the first results from a project that monitored volcanic activity on Io for over two years from 2013-2015. They managed to track the progress of about fifty eruptions on the moon’s surface over that period of time.
“On a given night, we may see half a dozen or more different hot spots,” said Katherine de Kleer, an author of the research. “Of Io’s hundreds of active volcanoes, we have been able to track the 50 that were the most powerful over the past few years.”
Io is the most volcanically active body in our solar system, often shooting magnificent plumes out into space. Unlike Earth, where volcanic activity is driven by the dynamic structure of the Earth’s interior, on Io, volcanic activity is driven by external, not internal forces. Jupiter’s gravity tugs on the moon so much in its orbit, that Io goes through something called tidal heating.
Near-infrared images of Io: Io is seen here in images taken in near-infrared wavelengths. Bright spots are eruptions on the moon’s surface. Credit: Katherine de Kleer and Imke de Pater, UC Berkeley
Just like our moon pulls on Earth’s water to create our tides, Jupiter pulls on Io, pulling the entire surface of the moon so much that it creates huge amounts of friction, which leads to heat, which leads to the large number of eruptions that we see today.
But while we know the basics of volcanic activity on Io, there are still a lot of specifics that remain elusive. This new research provides a lot more details to try and fill in the gaps in our knowledge, but the observations have also left a lot of questions. The researchers found that the eruptions weren’t as constant across the surface of the moon as they expected and that in some cases, the volcanic eruptions moved in a line across shockingly long distances–even across 500 kilometers (over 300 miles).
“While it stretches the imagination to devise a mechanism that could operate over distances of 500 kilometers, Io’s volcanism is far more extreme than anything we have on Earth and continues to amaze and baffle us,” de Kleer said.
Clearly, Io will continue to be a hot topic for years to come.