After scientists and students from Caltech made a research on the chemical matrix of Europa, Jupiter's icy moon, is thought to have table salt in its oceans.
The study was inspired by Galileo's mission in the 1990s, where he gathered data that suggested sulfate salts might be on the oceans of Europa, under its icy crust. Later on, other data collected by the Hubble Space Telescope failed to show that there were traces of sulfates in the ocean. It showed instead that common table salt may be what dictates the physical appearance of Europa.
The researchers did a survey on the moon's terrain and emphasized in their study on what they call the chaos terrain-the areas with patches; these are areas where disruptions were observed and were thought to be due to whatever underlying material was having a chemical reaction. "If anywhere was going to represent the internal composition, it would be these places," says Samantha Trumbo a graduate student with a major in Planetary Sciences at Caltech.
In this case, it is the ion collision and exchange that causes the formation of the chaos terrain. The collision of electrons with sodium chloride causes the release of chloride ions. The electrons then take the place of the chloride ions and they form a bond with the sodium ions, and this reaction causes the salt to change in color from white to yellowish. The same tone of yellow is observed to match with the rough patches on the surface of Europa. Now, observing the images from Galileo's mission, the yellowish tone may be attributed to the presence of sodium chloride.
"This could mean that the ocean chemistry is more similar to what we're used to on Earth and what we see at Enceladus, which is an ocean moon of Saturn," says Trumbo. If this is true, then Europa might be able to support life. "People think that, if there were a place elsewhere in the solar system where there might be life, Europa is a candidate," Trumbo added.
