NASA’s Juno spacecraft photographs Loki Patera, the largest lava lake ever seen on Jupiter’s moon Io

Water in the solar system is not breaking news. Planets have water in a solid state at their poles, just like the Moon also has it. For years, NASA has been trying to find water in a liquid state in other places beyond Earth, but the only planet that can potentially hold life and is close enough to make a trip to study is Mars. On the other hand, while searching for discoveries in the cosmos, NASA found a giant lake on Jupiter’s moon Io during the Juno mission, but not filled with water, during the exclusive mission to explore the giant planet.

NASA discovered a huge lake on Io

The NASA Juno mission focuses on exploring Jupiter, the largest planet in our solar system, and the primary goal is to collect data about the planet’s water abundance by looking for the presence of oxygen and hydrogen molecules. The atmosphere is mostly hydrogen and helium, but scientists have also spotted traces of methane and ammonia.

According to NASA, Jupiter was likely the first planet to be formed due to the presence of hydrogen and helium in the atmosphere, and it contains most of the dust and gas in the solar system that was not incorporated into the Sun. In 1995, the Galileo probe indicated that Jupiter is hotter than expected, and it is devoid of water. Meanwhile, the planet has 95 moons, with Io presenting one of the strongest volcanic activities in the solar system.

Using collected data from the camera aboard the spacecraft, during two flybys, the JunoCam captured an aerial view of Loki Patera, the largest lava lake ever seen. The lake is approximately 200 kilometers (127 miles) wide, and the surface appears to be smooth and reflective, which means the lava has cooled down fast, forming obsidian rock.

How was it discovered?

The infrared observations made with Juno’s Jiram (Jovian Infrared Auroral Mapper) pointed out that many volcanic depressions on Jupiter’s moon Io contain active lava lakes with cooler crusts in the center and hotter edges where lava is exposed, suggesting that magma constantly overturns and resurfaces. The discovery was made public by Juno’s principal investigator, Scott Bolton, during a press conference at the European Geophysical Union General Assembly in Vienna.

Another Juno co-investigator from the National Institute of Astrophysics in Rome, Alessandro Mura, revealed that the collected data suggests that 3% of Io’s surface is covered by molten lava lakes. Part of the research also suggests that some parts of Io’s surface are similar to obsidian glass, formed when lava cools down rapidly with minimal crystal growth.

The volcanic moon

Jupiter’s moons are split into two categories: the Galilean moons (Io, Ganymede, Europa, Callisto) and smaller satellites. Ganymede is the largest moon orbiting Jupiter, which NASA studies to learn about its possible liquid metallic core.

Io suffers from intense volcanic activity driven by the gravitational interactions between Jupiter, Europa, and Ganymede. These interactions create gravitational forces that distort Io’s orbit, generating internal friction that heats its interior and drives its extreme volcanism.

Implications for future research

The lava lakes captured by NASA’s Juno spacecraft provide a detailed insight into Io’s volcanic activity. These features align with what scientists expect from tidal heating, where the internal heat from gravitational flexing causes widespread melting and constant resurfacing of the moon’s crust, different from Earth, where tectonic plates are responsible for lava rising to the surface.

Jupiter is one of the planets humans could peek into back in February, when a rare alignment between cosmic objects happened in the solar system. One of the planets, Venus, can be seen frequently early in the morning.