Jupiter’s moon Europa glows in the dark, finds NASA

MUMBAI: The National Aeronautics and Space Administration has discovered that one of Jupiter’s moons, Europa, glows in the dark due to a relentless radiation attack. The discovery was made by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and later in Nature Astronomy on November 9, with Murthy Gudipati as the lead author.
Gudipati is a NASA scientist born and raised in South India. He holds his Masters from the University of Hyderabad and his PhD from the Indian Institute of Science, Bengaluru. In 2007 he joined JPL.
“We were able to predict that this nocturnal glare of ice could provide further information on the composition of Europa’s surface. The way this composition varies could give us clues as to whether Europa brings conditions suitable for life,” Gudipati said.
The discovery takes on significance in the context of NASA’s planning of a mission to Europe called Europa Clipper provisionally in 2024 that will contribute to the field of astrobiology.
According to the JPL, new laboratory experiments recreated Europa’s environment and found that the icy moon also shone on the night side. “The effect is more than just a visual,” JPL said.
“As the icy full moon of the ocean Europa orbits Jupiter, it resists a relentless blast of radiation. Jupiter hits the surface of Europa night and day with electrons and other particles, immersing it in high-energy radiation. But as these particles strike the surface of the moon, they could also do something otherworldly: make Europe glow in the dark, ”JPL said.
According to JPL, this new research describes for the first time what the glow would look like and what it might reveal about the composition of the ice on Europa’s surface.
Different saline compounds react differently to radiation and emit their unique glow. “To the naked eye, this glow sometimes appears slightly green, sometimes slightly blue or white, and with varying degrees of brightness, depending on the material,” says JPL.
Scientists used a spectrometer to separate the light into wavelengths and link the distinct “signatures”, or spectra, to different ice compositions. Most observations using a spectrometer on a moon-like Europa were taken using sunlight reflected on the day side of the moon, but these new results illuminated what Europa would look like in the dark.
“This is because Europa holds a huge global internal ocean that could seep to the surface through the moon’s thick ice crust. By analyzing the surface, scientists can learn more about what lies beneath,” he says.
Scientists have inferred from previous observations that Europa’s surface may be composed of a mixture of ice and salts commonly known on earth, such as magnesium sulfate (Epsom salt) and sodium chloride (table salt). “The new research shows that incorporating these salts into water ice under conditions similar to those of Europe and detonating it with radiation produces a glow,” according to JPL.
To study a laboratory model of Europa’s surface, the JPL team built a unique instrument called the Ice Chamber for European High-Energy Electron and Radiation (ICE-HEART) tests.
They took ICE-HEART to a high-energy electron beam facility in Gaithersburg, Maryland, and began the experiments with a completely different study in mind: to see how the organic material under Europa Ice would react to bursts of radiation.