NASA’s Juno mission measures the amount of oxygen on Europa. Jupiter’s ice-covered moon generates 1,000 tons of oxygen every 24 hours—enough to keep a million people breathing for a day. But the rate of oxygen production on Jupiter’s moon Europa is significantly slower than most previous studies. The results, published March 4 in the journal Nature Astronomy, were obtained by measuring hydrogen evolution from the surface of Jupiter’s icy moon using data collected by the Jovian Auroral Distributions Experiment (JADE) instrument.
Juno is equipped with 11 state-of-the-art scientific instruments designed to study the Jupiter system, including nine charged particle and electromagnetic wave sensors to study Jupiter’s magnetosphere. Juno is part of NASA’s New Frontiers program, which is operated at NASA’s Marshall Space Flight Center in Huntsville, Alabama, on behalf of the agency’s Science Mission Directorate in Washington. The Italian Space Agency (ASI) funded the Jovian InfraRed Auroral Mapper project. Lockheed Martin Space in Denver built and operates the spacecraft.
Europa, with an equatorial diameter of 1,940 miles (3,100 kilometers), is the fourth largest of Jupiter’s 95 known moons and the smallest of the four Galilean moons. Scientists believe that beneath its icy crust lies a vast internal ocean of salty water, and they are curious whether conditions to support life might exist below the surface.
This view of Jupiter’s icy moon Europa was captured by JunoCam aboard NASA’s Juno spacecraft during a close flyby of the mission on September 29, 2022. Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing: Kevin M. Gill CC BY 3.0
The paper’s authors estimate that the amount of oxygen produced is about 26 pounds per second (12 kilograms per second). Previous estimates range from a few pounds to more than 2,000 pounds per second (more than 1,000 kilograms per second). Scientists believe that some of the oxygen produced in this way could end up in the Moon’s underground ocean as a possible source of metabolic energy.
It’s not just water that attracts the attention of astrobiologists: the location of Jupiter’s moon also plays an important role in biological capabilities. Europa’s orbit places it directly in the center of the gas giant’s radiation belts. Charged or ionized particles from Jupiter bombard the icy surface, splitting water molecules in two, creating oxygen that can flow into Europa’s ocean.
“Europe is like a ball of ice slowly losing water in the flowing stream. Except in this case, the flow is a fluid of ionized particles around Jupiter by its unusual magnetic field,” said JADE scientist Jamie Szalay of Princeton University in New Jersey. “When these ionized particles collide with Europa, they destroy the water ice molecule on the surface, producing hydrogen and oxygen. In a sense, the entire ice shell is constantly being eroded by waves of charged particles washing over it.”
As Juno passed within 220 miles (354 kilometers) of Europa at 2:36 p.m. PST on September 29, 2022, JADE identified and measured hydrogen and oxygen ions that were created by bombarding charged particles and then “picked up” by Jupiter’s magnetic field , as he rushed past the satellite.
This illustration shows charged particles from Jupiter falling onto Europa’s surface, splitting frozen water molecules into oxygen and hydrogen molecules. Scientists believe that some of these newly created oxygen gases may migrate toward Europa’s underground ocean, as shown in the inset. NASA/JPL-Caltech/SWRI/PU
“When NASA’s Galileo mission flew past Europa, it opened our eyes to Europa’s complex and dynamic interaction with its environment. “Juno provided a new opportunity to directly measure the composition of charged particles ejected from Europa’s atmosphere, and we couldn’t wait to peer behind the veil of this fascinating water world,” said Szalay. “But what we didn’t realize was that Juno’s observations would give us such a tight constraint on the amount of oxygen produced on Europa’s icy surface.”
“Our ability to fly close to the Galilean moons during our extended mission has allowed us to begin pursuing a wide range of scientific investigations, including some unique opportunities to contribute to the study of Europa’s habitability,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute. Institute in San Antonio. “And we’re not done yet. More flybys of Jupiter’s moon and the first exploration of Jupiter’s nearby ring and polar atmosphere are still to come.”
Oxygen production is one of many aspects that NASA’s Europa Clipper mission will explore when it arrives at Jupiter in 2030. The mission has a complex payload of nine scientific instruments to determine whether Europa has habitable conditions. Now Bolton and the rest of the Juno mission team set their sights on another Jupiter world—the volcano-studded moon Io. On April 9, the spacecraft will approach its surface at a distance of about 10,250 miles (16,500 kilometers). The data Juno will collect will complement findings from past flybys of Io, including two extremely close approaches at a distance of about 932 miles (1,500 kilometers) on December 30, 2023 and February 3, 2024.
Jupiter through the eyes of the Hubble telescope
The giant planet Jupiter is revealed again in all its striped glory by NASA’s Hubble Space Telescope in these latest images taken on January 5-6, 2024, showing both sides of the planet. Hubble observes Jupiter and the other outer planets of the solar system annually as part of the Outer Planets Atmospheric Legacy (OPAL) program. These large worlds are shrouded in clouds and haze caused by strong winds, causing a kaleidoscope of ever-changing weather conditions.
NASA’s Hubble Space Telescope captured images of both sides of the giant planet Jupiter on January 5-6, 2024. NASA, ESA, STScI, Amy Simon (NASA-GSFC)
In the image on the left, the Classic Great Red Spot, much larger in volume than Earth, stands out prominently in Jupiter’s atmosphere. To the lower right, at a more southern latitude, is an object sometimes called the Red Spot Jr. This anticyclone was the result of a merger of storms in 1998 and 2000, and first turned red in 2006 before returning to a pale beige in subsequent years. This year it is slightly redder again.
The source of the red color is unknown, but may include a number of chemical compounds: sulfur, phosphorus, or organic matter. Staying in their lanes but traveling in opposite directions, Red Spot Jr. passes the Great Red Spot about once every two years. Another small red anticyclone appears in the far north.
In the right image – Storm activity is also evident in the opposite hemisphere. A pair of storms, a dark red cyclone and a reddish anticyclone, appear next to each other to the right of center. These storms rotate in opposite directions, indicating alternating high and low pressure systems. As for the cyclone, there is upwelling at the edges with clouds descending in the middle, which leads to clearing of the atmospheric haze.
The storms are expected to bounce off each other due to their clockwise and counterclockwise rotations. Toward the left edge of the image is Jupiter’s inner Galilean moon, Io, the most volcanically active body in the solar system despite its small size (only slightly larger than Earth’s Moon).
Hubble recognizes deposits from volcanic eruptions on the surface thanks to its sensitivity to blue and violet wavelengths. In 1979, NASA’s Voyager 1 spacecraft discovered Io’s pizza-like appearance and volcanic activity. Hubble picked up where Voyager left off, observing the restless moon Io year after year.