LOS ANGELES, Dec. 13 (Xinhua) -- Scientists with NASA's Juno mission to Jupiter have discovered that the volcanoes on Jupiter's moon Io are each likely powered by their own chamber of roiling hot magma rather than an ocean of magma.
The finding solves a 44-year-old mystery about the subsurface origins of the moon's most demonstrative geologic features, according to a study on the source of Io's volcanism published on Thursday.
About the size of Earth's moon, Io is known as the most volcanically active body in the solar system. The moon is home to an estimated 400 volcanoes, which blast lava and plumes in seemingly continuous eruptions that contribute to the coating on its surface.
The Juno spacecraft made extremely close flybys of Io in December 2023 and February 2024, getting within about 930 miles (1,500 kilometers) of its pizza-faced surface.
During the close approaches, Juno communicated with NASA's Deep Space Network, acquiring high-precision, dual-frequency Doppler data, which was used to measure Io's gravity by tracking how it affected the spacecraft's acceleration.
Through those flybys, the mission revealed more details about the effects of a phenomenon called tidal flexing, according to NASA.
"Juno's discovery that tidal forces do not always create global magma oceans does more than prompt us to rethink what we know about Io's interior," said lead author Ryan Park, a Juno co-investigator and supervisor of the Solar System Dynamics Group at NASA's Jet Propulsion Laboratory.
"It has implications for our understanding of other moons, such as Enceladus and Europa, and even exoplanets and super-Earths. Our new findings provide an opportunity to rethink what we know about planetary formation and evolution," he said. ■