Jupiter's Io -The Volcanic Epicenter of the Solar System

Boston University researchers published the first clear evidence of how gases from Jupiter’s tiny moon Io’s volcanoes can lead to the largest visible gas cloud in the solar system. Jupiter, the largest planet in the solar system, has a moon named Io that is just 100 km larger in radius than Earth’s Moon,  with over 100 active volcanic sites on Io making it the most active place for volcanic activity known anywhere.

In 1990, BU scientists discovered a large gas cloud – or nebula – of sodium atoms spanning great distances to either side of Jupiter.

“If this faint structure could be seen by the naked eye, it would be over ten times the size of the full Moon, and thus the largest permanently visible object in our solar system,” Michael Mendillo, professor of electrical and computer engineering and astronomy at BU explained. “Computer models suggested the types of escape processes needed to feed this giant nebula, but actual pictures of those sources eluded observers for many years.”

The research team from Boston University’s College of Engineering and Center for Space Physics (CSP) solved this problem by developing a novel way to photograph these sources using a high-definition imaging (HDI) system that combines several images into one clear picture.

The new images, published in the July 19th issue of the journal Nature, reveal two distinct sources of sodium atoms escaping from Io. One is a symmetrical cloud of escaping gas produced by collisions of the streaming ions and electrons in Jupiter’s so-called plasma torus. These plasma particles are trapped in Jupiter’s strong magnetic field and rotate with the planet’s 10-hour period, much faster than the 2-day orbital period of Io. “So, there is a continuous plasma wind hitting Io, causing sodium atoms to be sputtered from its atmosphere,” Mendillo explained.

Posted by Casey Kazan.

BU Story Link