Using data from Jupiter aurora distribution experiment (JADE) Instrument equipped NASA spacecraft Junoplanetary scientists calculated that the proportion of oxygen produced on Jupiter's icy moon Europa is significantly lower than in most previous studies.
This diagram shows charged particles from Jupiter impacting Europa's surface, splitting frozen water molecules into oxygen and hydrogen molecules. Scientists believe that some of these newly produced oxygen gas may migrate toward the moon's subsurface ocean, as depicted in the inset image. Image credit: NASA / JPL-Caltech / SWRI / PU.
With an equatorial diameter of 3,100 km (1,940 miles), Europa is the fourth largest of Jupiter's 95 known moons and the smallest of the four Galilean moons.
The moon has an internal liquid ocean and potentially habitable conditions beneath its frozen crust.
Its surface is constantly bombarded with radiation, which breaks down the icy crust into oxygen and hydrogen, most of which is either released from the surface and escapes into space, or remains and forms Europa's atmosphere.
The abundances of these atmospheric gases and ions, and consequently their production rates at the Earth's surface, are inferred primarily from remote sensing observations and are subject to large uncertainties.
“Europa is like an ice ball that slowly loses water in a flowing river,” said Dr. Jamie Zareh, a JADE scientist and researcher at Princeton University.
“However, the flow in this case is a fluid of ionized particles that are swept around Jupiter by Jupiter's unusual magnetic field.”
“When these ionized particles hit Europa, they break up the water ice on the surface molecule by molecule, producing hydrogen and oxygen.”
“In a sense, the entire ice shell is being continuously eroded by the waves of charged particles being launched.”
In the new study, Zarai and colleagues analyzed data from a flyby of Europa conducted by the Juno spacecraft on September 29, 2022. On this flight, the spacecraft flew 353 kilometers (219 miles) above Europa's surface.
They used a JADE instrument to extract abundant amounts of different pickup ions. Pick-up ions are charged particles produced by the destruction of atmospheric neutrals when they collide with high-energy radiation or other particles.
From these data, they calculate that about 12 kg of oxygen is produced every second on Europa's surface.
This is at the lower end of the range of 5 to 1,100 kg per second estimated from previous models.
The results suggest that Europa's surface may have less oxygen than previously thought, meaning that Europa's oceanic habitat is narrower. .
“Flying so close to the Galileo satellite during its long-duration mission allowed us to begin working on a wide range of science, including the unique opportunity to contribute to the study of Europa's habitability,” Juno Principal Investigator said researcher Dr. Scott Bolton. Southwest Research Institute.
“And we're not done yet. More moon approaches and the first exploration of Jupiter's close rings and polar atmosphere are still to come.”
of findings It was published in the magazine natural astronomy.
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JR Zarai other. Production of oxygen by dissociation of Europa's water and ice surfaces. Nat Astron, published online March 4, 2024. doi: 10.1038/s41550-024-02206-x
Source: www.sci.news
