NASA’s Juno mission provides an insight into Europa’s oxygen production.

This view of Jupiter’s icy moon Europa was skillfully captured by the JunoCam imager aboard NASA’s Juno spacecraft. The snapshot was taken during the spacecraft’s close flyby on September 29, 2022, providing a unique perspective on the enigmatic features that characterize Europa’s icy surface.

Beneath its icy exterior, Jupiter’s moon Europa serves as a prolific oxygen factory, churning out an impressive 1,000 tons of oxygen every 24 hours. Scientists from NASA’s Juno mission to Jupiter have recently recalibrated the rate of oxygen production on Europa, revealing a more conservative estimate compared to earlier studies. Published on March 4 in Nature Astronomy, these findings stem from measuring hydrogen outgassing from Europa’s surface. The spacecraft’s Jovian Auroral Distributions Experiment (JADE) instrument played a crucial role in collecting the data that led to this insightful discovery.

In their published paper, the authors project the production of approximately 26 pounds of oxygen every second (12 kilograms per second) on Jupiter’s moon Europa, a more conservative estimate compared to previous ranges of a few pounds to over 2,000 pounds per second (over 1,000 kilograms per second). This substantial oxygen output raises intriguing possibilities, as scientists contemplate the potential for some of this oxygen to migrate into Europa’s subsurface ocean, potentially serving as a source of metabolic energy.

With an equatorial diameter of 1,940 miles (3,100 kilometers), Europa stands as the fourth largest among Jupiter’s 95 known moons and the smallest of the four Galilean satellites. Scientists are particularly intrigued by the possibility of a vast internal ocean beneath its icy crust, fueling speculation about the potential for life-supporting conditions below the moon’s surface.

Jupiter’s charged particles impact the surface of Europa.

Beyond its intriguing water dynamics, Europa’s orbital position in the heart of Jupiter’s radiation belts captures the interest of astrobiologists. Positioned squarely within the gas giant’s radiation belts, Europa experiences a constant bombardment of charged or ionized particles from Jupiter. This relentless interaction with the moon’s icy surface leads to the splitting of water molecules, generating oxygen. The potential migration of this oxygen into Europa’s ocean further adds to the biological possibilities that scientists explore in their quest for understanding the moon’s potential for sustaining life.

Describing Europa as akin to an ice ball gradually losing its water in a cosmic stream, JADE scientist Jamey Szalay from Princeton University elucidates the unique scenario. Europa’s environment involves a fluid of ionized particles propelled around Jupiter by its powerful magnetic field. As these ionized particles collide with Europa, they meticulously disassemble water-ice molecules on the surface, generating hydrogen and oxygen. This ongoing process resembles a continuous erosion of the entire ice shell, with waves of charged particles acting like cosmic tides washing over Europa’s surface.

Juno Mission Captures the Bombardment: Insights into Europa’s Oxygen Production and Upcoming Io Encounter.

Reflecting on NASA’s Galileo mission that previously unveiled the intricate dynamics of Europa’s interaction with its environment, JADE scientist Jamey Szalay acknowledges the transformative role of Juno in expanding our understanding. Juno, equipped with advanced capabilities, directly measures the composition of charged particles emitted from Europa’s atmosphere, providing unprecedented insights into this captivating water world. Szalay expresses surprise at the tight constraint Juno’s observations provided on the amount of oxygen produced on Europa’s icy surface.

Juno, armed with 11 cutting-edge science instruments, including nine charged-particle and electromagnetic-wave sensors, is instrumental in unraveling the mysteries of Jupiter’s magnetosphere and the celestial dance between Europa and its cosmic surroundings.

Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio, underscores the significance of the extended mission, enabling close encounters with the Galilean satellites and paving the way for diverse scientific investigations. This extended mission has presented unique opportunities to contribute to the exploration of Europa’s habitability. Bolton expresses enthusiasm for the ongoing journey, highlighting the prospect of more moon flybys and the groundbreaking exploration of Jupiter’s close ring and polar atmosphere. The Juno spacecraft continues to chart new territories, promising further revelations in the captivating narrative of our solar system’s largest planet and its enigmatic moons.

With the Juno mission team led by Scott Bolton at the helm, attention now turns toward another captivating Jovian moon, Io, renowned for its volcanic landscapes. On April 9, Juno is poised to approach within approximately 10,250 miles (16,500 kilometers) of Io’s surface. This upcoming encounter follows in the footsteps of past Io flybys, including two remarkably close approaches at about 932 miles (1,500 kilometers) on December 30, 2023, and February 3, 2024. The data collected during these encounters is expected to deepen our understanding of Io’s volcanic activity and contribute valuable insights to the ongoing exploration of Jupiter’s diverse and dynamic moon.