Europa, a frozen moon near Jupiter, is considered one of the most suitable habitat for the worlds in the Solar system. The first time it examined in detail the probe “Voyager 1” in 1979, showing a surface almost devoid of large craters. This suggests that water regularly follows up by renewing the surface of the satellite. Europe is also dotted with long hollows, folds and ridges, potentially made of icebergs floating in melted water or slush. But in the late 1990-ies Europe has become really interesting.
Mission Galileo found evidence that under the surface of Europa is a liquid ocean of salty water. The fact that it is salty, gives us to understand that water can come in contact with the rock — a process that can provide energy in water to power microbial life.
But observations were too few and they were limited, so we can’t specifically say how deep and salty this ocean — not to mention what salt. And now, a new study published in Science Advances, indicates that it could be normal table salt (sodium chloride) as on Earth. The consequences of this discovery will be important for the possible existence of life hidden in the depths of Europe.
Scientists believe that hydrothermal circulation in the ocean associated with hydrothermal vents may in a natural way to enrich the ocean sodium chloride as a result of chemical reactions between the ocean and the stone. On Earth, hydrothermal vents are considered to be the source of life, for example, bacteria. Discovered that the plumes emitted from the South pole of Saturn’s moon Enceladus, which has a similar ocean contain sodium chloride, which makes Europe and Enceladus an even more attractive object for research.
Is there life on Enceladus?
If you look at the spectrum of light (split light, depending on wavelength) reflected from the surface, we can figure out what substances are there. In this case, scientists have found water ice. But there are two others: “hydrated” sulfuric acid and sulfate salt. Where are they? Scientists studying the interior of Europe, or those who examine the astrobiological potential of this moon ocean, ask an interesting question: did these materials from within Europe?
Like our moon and Earth, tidal Europe associated with Jupiter, that is, always looks at him the same side. Observations of the Galileo revealed the presence of “hydrated” sulfuric acid on the other side of Europe, which represents the “rear hemisphere”. To make sulfuric acid from water ice, the source of sulphur and energy for a chemical reaction. Part of this may appear from the inside of the moon in the form of sulfate salts, the part can be delivered by meteorites, but the most likely explanation is that all this is born of the volcanic moon IO.
Sulfur could be thrown into space by the volcanoes of IO and eventually came to Europe. Moving faster than Europe, this sulfur most likely came on the back of Europe, and plunged into the ice. The energy needed for this came from electrons in the radiation belts of Jupiter. For the most part, they fly around Jupiter faster than Europe, fall on her backside and takes a lot of energy.
Measurements also showed the presence of sulfate salts like magnesium sulfate (Epsom salt), but it is unclear where they come from.
Scientists came to the conclusion that the direction of Europe, toward the side of its orbit, protected from the sulfuric bombing, may be the best place to look for evidence of what salt actually exist within Europe.
In the visible part of the spectrum is characterized by “centers of color” — which appear during the irradiation of highly energetic electrons. With the help of the Hubble space telescope managed to find these color centers in the spectrum of Europe and also hell of the surface located exclusively in the “safe” place on the side of the moon, looking at the orbit, and there was sodium chloride. Everything shows that he really could go from the depths of Europe.
Life as we know it, needs liquid water and energy. The fact that Europe has liquid ocean, tells us that there is liquid water and a source of energy that does not allow it to freeze. But ocean chemistry is also important. Salt water freezes at a lower temperature than pure water, and thus such water becomes more habitable.
Salt, especially sodium ions in table salt, also play an important role in several metabolic processes in plant life and animals. On the contrary, some other salts such as sulphates, can interfere with life. Maybe salt is just part of the natural layers of ice. But for those who hopes to find on Europa life detection of sodium chloride, which is great news.
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