Jupiter’s moon Io is one of the strangest places in the known universe. It’s surface is constantly being remade by hundreds of alien volcanoes and geysers spewing molten iron, sulfur, and silicate rock as it spins around Jupiter at 40,000 mph.

The surface of Jupiter’s moon Io was captured in infrared by the Juno spacecraft’s Jovian Infrared Auroral Mapper (JIRAM) imager as it flew by at a distance of was about 50,000 miles (80,000 kilometers) on July 5, 2022. Bright spots show higher temperatures. All the geologic activity is caused by an unusual source – Jupiter’s immense gravity and magnetic field squeezing the moon.

The space probe Juno has been orbiting Jupiter since 2016. After studying the gas giant, Juno flew by Jupiter’s moon Ganymede in 2021 and by Europa earlier this year.

Io is nearly our Moon’s twin in size – but two worlds could not be more different. Our Moon’s gray, stable appearance contrasts with Io’s ever-changing yellows, oranges, and reds; mostly forms of sulfur in various states. Cold sulfur makes white frost while hot sulfur is red.

Scientists hope to gather more data on the moon’s volcanoes and its magnetism – which play a “tug of war” to form Jupiter’s auroras. An electric current called the “Io flux tube” flows between the two bodies, and focuses at the poles. This causes Jupiter to have auroras that are 1000 times a large and powerful as Earth’s, as seen below by Hubble. While Earth’s auroras are caused by the solar wind interacting with Earth’s magnetic field, Jupiter’s are made from Io’s “space lava.”

This video from NASA shows how Jupiter’s magnetic field interacts with another of its moons.

Juno will continue to fly by Io for another 18 months, if it can survive the intense radiation.