European Space Agency set to launch Jupiter Icy Moons Explorer (Juice): What is the mission about

Only two other spacecraft have ever examined Jupiter: the Galileo probe, which orbited the gas giant between 1995 and 2003, and Juno, which has been circling the planet since 2016. Notably, by the time Juice reaches Jupiter, another spacecraft, NASA’s Europa Clipper, would already be orbiting the planet — scheduled to be launched in October this year, Europa Clipper would arrive at Jupiter in 2030 and aims to study its Europa moon.

What is the Jupiter Icy Moons Explorer (Juice) mission?

According to ESA’s website, the Juice “will make detailed observations of the giant gas planet and its three large ocean-bearing moons — Ganymede, Callisto and Europa”, by using remote sensing, geophysical and in situ instruments.

Scientists for quite some time have known that these three moons of Jupiter possess icy crusts, which they believe contain oceans of liquid water underneath, making them potentially habitable. Juice will help probe these water bodies by creating detailed maps of the moons’ surfaces and enable the scientists, for the first time, to look beneath them.

Although the mission will examine all three moons, the main focus will be on Ganymede, as it is the largest moon in the Solar System — larger than Pluto and Mercury — and the only one to generate its own magnetic field. Juice, which will move into Ganymede’s orbit after approximately four of arriving at Jupiter, will “use its suite of ten sophisticated instruments to measure how Ganymede rotates, its gravity, its shape and interior structure, its magnetic field, its composition, and to penetrate its icy crust using radar down to a depth of about nine km.,” ESA said.

Another primary goal of the mission is to create a comprehensive picture of Jupiter by trying to understand its origin, history and evolution. Scientists believe that this would help them provide “much-needed insight into how such a planetary system and its constituents are formed and evolved over time, as well as revealing how possibly habitable environments can arise in Jupiter-like systems around other stars.”

Juice will also analyse the chemistry, structure, dynamics, weather, and climate of Jupiter and its ever-changing atmosphere.

Is Juice capable of detecting life?

As mentioned before, as the three moons, Ganymede, Callisto and Europa, are believed to hold immense amounts of water, which could be around six times more than the volume of water in Earth’s oceans, there is a possibility that life is present on them. According to ESA, life on these moons could be in the form of microbes. “More advanced species might also be present, like the ones we detect in deep-sea trenches and at hydrothermal vents on Earth, such as various kinds of coral, worm, mussel, shrimp and fish,” it added.

However, Juice isn’t equipped to detect life. What it is capable of is finding out whether there could be places around Jupiter, inside the icy moons, where the necessary conditions, such as water, biological essential elements, energy, and stability, to sustain life are present.

Speaking to Space.com, Adam Masters, senior lecturer in space and atmospheric physics at Imperial College London and a member of the team that built one of the scientific instruments for Juice, said, “If life exists on these moons, we expect it to be in the water, and that’s very hard to access.” This is because, she added, it’s not yet possible to go very deep underneath the ice crusts, where life might be present.