"Io represented a big mystery because its surface doesn't hold a record of its history the way that the surfaces of less active moons do." When you purchase through links on our site, we may earn an ...

Io is the most volcanic body known to science, and researchers have puzzled over its history for years. A new report suggests it was born this way. This image revealing the north polar region of the ...

Why it's so special: NASA's Juno spacecraft has captured the closest views of Io since NASA's Galileo spacecraft imaged the volcanic world in 2001. Passing within just 930 miles (1,500 kilometers) of ...