🧬 The foundations of life on Jupiter's moons?

Essential ingredients for life could be far more widespread than previously thought. Jupiter's moons may have inherited them from their very formation. These icy worlds, long perceived as inert, are gradually revealing a rich chemical history.

The Galilean moons, such as Europa or Ganymede, have intrigued scientists for decades. Their icy surfaces likely conceal liquid oceans, considered conducive to the emergence of life forms. These environments particularly attract researchers because they combine water, energy, and complex chemistry.


At the heart of this chemistry, complex organic molecules play a key role. Composed mainly of carbon, oxygen, and nitrogen, they are seen as building blocks of prebiotic chemistry. Their presence in the Solar System is not new, as they have already been identified on Enceladus, a moon of Saturn.

A study shows that these molecules might also have participated directly in the formation of Jupiter's moons. An international team, including researchers from CNRS Earth & Universe, used advanced numerical models to trace these ancient processes.

The scientists simulated the evolution of the protosolar nebula, the cloud of gas and dust that gave rise to the Sun and planets. They also modeled the circumjovian disk, a similar structure surrounding Jupiter during its formation, from which its moons emerged.

Their approach integrates an often underestimated element: the movement of dust grains. These particles migrate both radially and vertically, traversing zones subjected to varying intensities of ultraviolet radiation. This differentiated exposure strongly influences the chemical reactions on their surfaces.

The simulations show that grains coated in ices, like methanol or mixtures of carbon dioxide and ammonia, can produce complex organic molecules under the combined effect of heating and UV radiation. Laboratory experiments have confirmed these conditions as favorable for their formation.

By cross-referencing their results with experimental data, the researchers estimate that a significant portion of these molecules was incorporated into the materials that formed the Galilean moons. In other words, these celestial bodies may have inherited an elaborate organic chemistry from their very origin.

This discovery strengthens the interest in these moons, already targeted by the JUICE and Europa Clipper missions. These probes could directly detect these compounds and better understand their distribution. Such confirmation would provide valuable clues about the biological potential of these environments.