Jupiter’s moon revealed: Juno’s flybys reveal Io’s Lake of Fire | Scientific news

NASA’s Juno spacecraft captured stunning images during close flybys of Jupiter’s moon Io that revealed two remarkable features: a towering mountain and an eerily smooth lake of cooling lava. These discoveries shed light on the moon’s volcanic activity and unique landscape.

Artist’s concept of Loki Patera on Io using data captured by Juno. (Image credit: NASA).


  • Juno’s close encounters with Io provided the first-ever close-up images of the moon’s northern latitudes.
  • Juno’s data turned into animations also showed Loki Patera, a 200-kilometer-long lava lake.
  • The surface of the lake, captured in specular reflections, looked as smooth as glass and was reminiscent of obsidian glass formed by volcanic activity on Earth.

New Delhi: Researchers have used data collected during two recent flybys of the Jovian moon Io by NASA’s Juno spacecraft to reveal the volcanic moon’s hellish landscape. There are more than 400 active volcanoes on Io’s surface, with the spacecraft revealing dramatic features such as a glass-smooth lake of cooling lava and a steep mountain spire. The findings were unveiled at the European Geophysical Union Assembly in Vienna.

In Search of Loki Patera of Io (Artist's Concept)

Juno came within 1,500 kilometers of Io’s surface in December 2023 and February 2024. Maps generated using data collected by the microwave radiometer on Juno show that Io has a surface that is relatively smooth compared to Jupiter’s other Galilean moons, and that its poles are colder than the mid-latitudes.

Io's 'Steeple Mountain' (artist concept)

Juno lead researcher Scott Bolton said: “Io is simply littered with volcanoes, and we’ve seen a few in action. We also got some great close-ups and other data from a 200 kilometer long lava lake called Loki Patera. There are amazing details showing these crazy islands, embedded in the middle of a potential magma lake rimmed with hot lava. The specular reflection that our instruments captured from the lake suggests that parts of Io’s surface are as smooth as glass, reminiscent of volcanically created obsidian glass on Earth.”

Juno's conquest of Io on April 9, 2024. Credit: Gerald Eichstädt/Thomas Thomopoulos, CC BY.

Revealing the secrets of Jupiter

The spacecraft not only provides fascinating insights into Io’s geological features, but also reveals Jupiter’s secrets. The spacecraft flies closer to the gas giant’s north pole with each pass, providing high-resolution data on Jupiter’s polar cyclones. Comparing the poles has highlighted the fact that not all cyclones are created equal. For example, the central polar cyclone on Jupiter has a weak microwave signature compared to the surrounding cyclones. The Juno team hopes to create an increasingly detailed three-dimensional map of the polar cyclones.