Why is Jupiter’s moon Europa believed to have life under its surface?

Quiet surrounding with crickets’ sound and the rustle of leaves as the cold breeze blow. Looking up in a night sky with the full Moon’s perfect scene adds to the relaxing feeling and beauty that most of us loved to see.

Among all celestial bodies, Moon is the easiest to be seen in the sky. The planet’s only natural satellite hovers above us bright and round until it seemingly disappears for a few nights. The Moon’s movements affect many phenomena on Earth-changing of tides, seasons, and life.

The Moon is a little more than ¼ of the Earth’s size. It helps stabilize the planet’s wobble, also resulting in the stabilization of the climate. Therefore, it plays a very crucial part of all life on Earth. (click here for more details)

The Moon is not just the only one existing in the Solar System; more than 200 of them come in various sizes, shapes, and types, according to NASA. Mostly have no air, and only a few have atmosphere and even have hidden oceans. (click here for more details)

Since oxygen is absent in moons, there will be no chance of survival for any organism. Jupiter, the fifth planet from the Sun, has 79 total moon, 53 are named, and 26 await official names. Europa or also known as Jupiter II is one of Jupiter’s Moon, and the largest among all other moons in the Solar System is believed that would be able to sustain life.

According to NASA’s scientists, Europa has an ocean under the surface ice shell, which could be a formation from the breakdown of water-containing minerals due to either tidal forces or radioactive decay. This may have implications for other moons in the Solar System. However, the work is not yet peer-reviewed but is presented for the first time at the Goldschmidt virtual conference.

With the use of ground-based telescopes, scientists found out that Europa has mostly water ice surface. In 1979, the two Voyager spacecraft passed through the Jovian system and found evidence that beneath the ice crust is an ocean liquid water or slushy ice. The Galileo spacecraft voyage and the ground-based telescopes on Earth have increased scientists’ confidence for a Europa ocean. (click here for more details)

They estimated the ice shell to have a thickness of 10 to 15 miles, floating on an ocean 40 to 100 miles deep. Although Europa is only ¼ the diameter of Earth, its ocean may contain twice as much water as all of the Earth’s oceans combined. The ocean may be leaking out into space that a passing spacecraft might even be able to get a sample of the ocean’s water. In search of a promising place for life beyond the Earth, Europa could possibly be the answer because of the presence of its vast and unfathomable deep ocean.

Researchers from NASA’s Jet Propulsion Laboratory in California modeled geochemical reservoirs within Europa’s interior with data from Galileo’s mission. According to Mohit Melwani Daswani, lead researcher, they were able to model the core silicate layer’s composition and physical properties and the ocean. They found out that different minerals lose water and volatiles at different depths and temperatures. They added up the volatiles that is estimated to have been lost from the interior and found out that they are consistent with the current ocean’s predicted mass, meaning that they are probably present in the ocean.

Researchers believed that ocean worlds like Europa are formed out of metamorphism, the heating and increasing pressure caused by radioactive decay, or later subsurface tidal movement would cause the breakdown of water-containing minerals and the release of the trapped water.

Daswani stated that their simulations, coupled with data from the Hubble Space Telescope, had shown chloride on Europa’s surface. Therefore its composition became more like the Earth’s oceans and believed it to be quite habitable for life. He added that Europa is one of the best chances of finding life in the Solar System.

NASA’s Europa Clipper mission will further explore the moon’s habitability. The researchers teamed up with Nantes and Prague groups to identify if volcanoes on the seafloor may have contributed to the evolution of the chloride-rich water on Europa. Recently, NASA has released new high-resolution photos of Europa showing possible exploration sites to test these findings. (click here for more details)