New NASA photos show fiery eruptions from volcanos on Jupiter's moon

In new images captured by NASA's Juno spacecraft, fiery volcanic activity is seen erupting across Jupiter's moon, Io.

Io is the third-largest of Jupiter's four Galilean moons and is the most volcanically active celestial body in our solar system, with roughly 400 active volcanos, according to the agency.

Marking the second flyby of Jupiter's scorching moon in the last 22 years, NASA's orbiter came within about 930 miles of Io and captured two twin volcanic plumes spewing into space from the moon's surface.

The first approach by Juno took place last year on Dec. 30.

The highly detailed images of Io, captured by Juno on Feb. 3, show the moon partially illuminated against the pitch-black backdrop of space.

"The second pass went predominantly over the southern hemisphere of Io, while prior flybys have been over the north," NASA said in a press release on Wednesday. "There's a lot to see in these photos," the agency noted, explaining, "There's evidence of an active plume, tall mountain peaks with well-defined shadows, and lava lakes — some with apparent islands."

The exact composition of Io remains unknown to researchers, however, NASA believes the moon is likely composed of molten sulfur or silicate rock while its atmosphere is made primarily of carbon dioxide.

While Io's surface shows a hotbed of volcanic activity in the images, what scientists don't yet know is how the moon's "volcanic engine" operates and if the moon has a "global magma ocean" raging below its hardened exterior.

"The twin flybys are designed to provide new insight into how Io's volcanic engine works and whether a global magma ocean exists under Io's rocky surface," NASA said in a post on X.

Io is the innermost celestial body of Jupiter's four massive moons, and scientists believe its gravitational position lends way to its powerful volcanic activity.

"Io is caught in a tug-of-war between Jupiter's powerful gravity and the smaller pull from two neighboring moons, churning its insides and creating eruptions and lakes of lava that cover its surface," NASA said.

Jupiter's four Galilean moons were discovered by Italian astronomer Galileo Galilei in 1610.

NASA's Juno spacecraft launched from Earth in 2011 and entered Jupiter's orbit in 2016. The spacecraft's mission was initially completed in 2021, however, NASA extended the mission through Sept. 2025 to further explore the planet's moons.