Jupiter’s icy moon Europa could give the phrase “moonlight” a whole new meaning. A series of new experiments by NASA scientists suggest that the icy moon shines, even on its night side.
As Europa, the frozen moon ( made up mostly of water ice and various salts ) and filled with oceans, orbits the gaseous planet Jupiter, it withstands a relentless blast of radiation. Jupiter strikes the surface of Europa day and night with electrons and other particles, bathing it in high-energy radiation . And, as these particles hit the moon’s surface, they make Europa glow in the dark.
On Earth, when the Moon shines in our sky, what allows us to see it is because it reflects sunlight. This is true for most bodies in the solar system, but Jupiter’s moons are out of the ordinary by existing in a fiercely radioactive environment where they are constantly bombarded with a wide variety of subatomic particles from the gas giant.
To better understand the effects of this enormous radiation on a moon like Europa , scientists created a laboratory mockup of Europa’s surface at a high-energy electron beam facility in Gaithersburg, Maryland, and used an instrument called the Ice Chamber. for Europe’s High Energy Electron and Radiation Environment Testing (ICE-HEART).
So when the researchers simulated that interaction in the lab by firing electrons at samples of salty ice, the ice glowed . The brightness of that glow depended on the type of salt in the ice, according to the researchers in their study published in the journal Nature Astronomy.
They found that when the ice on the surface of this moon, which contains magnesium sulfate (also known as Epsom salt) and sodium chloride (or table salt) seeping from the inside, glowed in the dark and that glow it varied with the composition of the ice. This means that the “dark” side of Europa actually has a variable brightness that is sometimes slightly green, or blue or white. (In fact, if the moon wasn’t bombarded by Jupiter’s radiation, it would look like Earth’s moon, dark on the far side.)
If this curious never-before-seen moonlight is confirmed over Europa, a future mission, such as the Europa Clipper spacecraft scheduled by NASA for the mid-2020s, could give us some insight into the salinity of the ocean believed to lurk beneath. the icy crust of Europa and many other details in its flybys orbiting Jupiter. This discovery is very interesting, as the underground ocean of Europa is considered one of the most promising places to search for extraterrestrial life in the solar system.
“The way in which this composition varies could give us clues as to whether Europe harbors suitable conditions for life”, clarifies Murthy Gudipati, leader of the study.
Europa is home to a huge ocean, and by studying the surface, experts hope to find out if life lurks in the vast body of water. Although the mission is not intended to search for life, we cannot miss the opportunity to conduct a detailed reconnaissance of Europe and see if it is capable of supporting it. Understanding the habitability of Europa will help scientists better understand how life developed on Earth and the potential to find life beyond our planet .
Referencia: M.S. Gudipati, B.L. Henderson and F.B. Bateman. Laboratory predictions for the night-side surface ice glow of Europa. Nature Astronomy. Published online November 9, 2020. doi: 10.1038/s41550-020-01248-1.
