Europa’s Interior Suggests Slow Evolution, Possibly Habitable Environment for Alien Life

Arizona State University (ASU) researchers Kevin Trinh, Carver Bierson, and Joe O'Rourke of the School of Earth and Space Exploration explore the possibility of Europa created from low initial temperatures and relate this to its potential to host alien life.

Main Composition of Icy Moon Europa

Slightly smaller than the Earth's moon, Europa is one of the most promising heavenly bodies to search for signs of life outside our planet. Among all the moons of Jupiter, Europa is of particular interest to astronomers due to its potential evidence for nutrients, energy, and water. These elements provide a habitable environment for possible life forms outside the Earth.

Scientists believe that Europa comprises four layers: ice shell, saltwater ocean, rocky mantle, and metallic core. Its ocean touches the rocky seafloor just like Earth, providing a rock-water combination favorable for the formation of alien life. It is also assumed that the seafloor contains volcanoes that can provide the energy and nutrients necessary for a biosphere.

Europa's ocean composition depends on temperature and pressure compositions where water contacts the rock. The nature of the rock-metal interior in Europa provides an overview of its slow evolution.

New Insight to Europa's Origin

Studying the origin of the ocean on Europa is crucial because the chemical ingredients and physical conditions during its formation can give clues about the icy moon's ability to support alien life; in the research made by ASU scientists, three cases related to the moon's initial state after the accretion process were investigated. These include the beginning of the metamorphic ocean, the delay in forming the metallic core, and the limited volcanic activity on the seafloor.

Some scientists speculated that the ocean layer in Europa might have a metamorphic origin. Using a computer code written by Trinh, the team wanted to show that if hydrated rocks were the foundations of Europa, their interior must be hot enough to release the water directly from the rocks to give way to ocean and ice shells.

Most scientists who study Europa conclude that it was formed with a metallic core during or after the accretion process. This prediction was contradicted by the ASU study, which suggests that the icy moon might take billions of years after accretion before forming the metallic core. In short, it reframes Europa as a heavenly body whose interior has slowly evolved over its lifetime.

The metallic core of Europa is deeply connected to its internal heat, which could have driven volcanic activities on the seafloor and contributed to an environment that can support life. It has been a mystery to scientists how this heat is generated throughout a moon, but Trinh's code challenged this assumption. It suggests that this icy moon was formed as a combination of rock, ice, and metal.

Another conclusion made from the research is the possibility that the seafloor in Europa was cooled and hydrated. There could also be limited hydrothermal and volcanic activity on the seafloor of this Jovian moon. These conditions could be the factors that hinder Europa's potential to provide a habitable environment.