A montage of Jupiter and its volcanic moon Io, taken during by the New Horizons spacecraft – en route to Pluto – in early 2007. Notice the volcanic plume above Io’s darkened surface. Image via NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Goddard Space Flight Center/Cosmos.
When we hear about volcanoes, we naturally tend to think of some of Earth’s most famous ones, including the Hawaiian volcanoes, Krakatoa or Mount St. Helens. Earth is a very volcanically active place; however, it is not the most active in the solar system. That would be Jupiter’s moon Io.
We on Earth first learned about Io’s volcanoes nearly 40 years ago, when NASA’s Voyager 1 spacecraft flew past this Jovian moon. Now, scientists have completed a comprehensive new peer-reviewed report on Io’s volcanoes, first published in The Astrophysical Journal on June 21, 2019, based on ground-based observations. The report covers five years of observations from 2013-2018, using advanced instrumentation on the Keck and Gemini telescopes.
Scientists had already known how volcanically active Io is. Its surface is dotted with hundreds of active volcanoes, despite this moon’s small size and its location at Jupiter’s orbit, much farther from the sun than Earth, in a ...