This is Part-2 of the series, ‘searching for home elsewhere.’ Part one explored Venus. Let’s look at a better and more stable candidate today.
Europa, or Jupiter II, is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 79 known moons of Jupiter. It is also the sixth-largest moon in the Solar System. Europa was discovered in 1610 by Galileo Galilei and was named after Europa, the Phoenician mother of King Minos of Crete and lover of Zeus (the Greek equivalent of the Roman god Jupiter).
Slightly smaller than Earth’s Moon, Europa is primarily made of silicate rock and has a water-ice crust and probably an iron–nickel core. It has a very thin atmosphere, composed primarily of oxygen. Its surface is striated by cracks and streaks, but craters are relatively few. In addition to Earth-bound telescope observations, Europa has been examined by a succession of space-probe flybys, the first occurring in the early 1970s.
Europa has the smoothest surface of any known solid object in the Solar System. The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath the surface, which could conceivably harbor extraterrestrial life.
As per NASA Scientists, Europa’s ice shell is 10 to 15 miles (15 to 25 kilometers) thick, floating on an ocean 40 to 100 miles (60 to 150 kilometers) deep. So while Europa is only one-fourth the diameter of Earth, its ocean may contain twice as much water as all of Earth’s oceans combined. Europa’s vast and unfathomably deep ocean is widely considered the most promising place to look for life beyond Earth. A passing spacecraft might even be able to sample Europa’s ocean without landing on the moon’s surface because it is possible that Europa’s ocean may be leaking out into space.
While no plumes were observed while the Galileo spacecraft was in the Jupiter system in the 1990’s, more recent observations from telescopes such as Hubble Space Telescope, as well as a reanalysis of some data from the Galileo spacecraft, have suggested that it is possible that thin plumes of water are being ejected 100 miles (160 kilometers) above Europa’s surface. In November 2019, an international research team led by NASA announced they had directly detected water vapor for the first time above Europa’s surface. The team measured the vapor using a spectrograph at the Keck Observatory in Hawaii that measures the chemical composition of planetary atmospheres through the infrared light they emit or absorb.
If the plumes do exist, and if their source is linked to Europa’s ocean, then a spacecraft could travel through the plume to sample and analyze it from orbit, and it would essentially be analyzing the moon’s ocean (the Cassini spacecraft performed this feat at Saturn’s moon Enceladus, which is known to have an ocean spraying into space). Even if Europa isn’t ejecting free samples into space, a 2018 study concluded that samples of Europa’s ocean could get frozen into the base of the moon’s ice shell, where the ice makes contact with the ocean. As the ice shell distorts and flexes from tidal forces, warmer and less-dense ice would rise, carrying the ocean samples to the surface where a spacecraft could analyze it remotely, using infrared and ultraviolet instruments, among others. Scientists could then study the material’s composition to determine whether Europa’s ocean might be hospitable for some form of life.
Life on Europa
Europa has a very thin oxygen atmosphere, but it is far too tenuous for humans to breathe. From the surface of Europa, Jupiter appears 24 times larger than the moon appears in our sky. Europa’s magnetic field shields its surface from Jupiter’s deadly radiation. Europa is thought to have a liquid water ocean underneath its icy exterior. Access to this liquid water ocean is a major difficulty, but the abundance of water on Europa is a benefit to any considerations for colonization. Not only can water provide for colonists’ drinking needs, it also can be broken down to provide breathable oxygen. Oxygen is also believed to have accumulated from radiolysis of the ice on the surface that has been convected into the subsurface ocean and may prove sufficient for oxygen-using marine life.
So what’s the conclusion?
Oh Hell Yeah! Europa might be the best bet for human’s survival after Earth in the solar system. You could see the gigantic volcano on Jupiter from Europa, sun will be considerably far away, the weather will be old but Europa offers both oxygen and water. Rejoice, Europa even has a magnetic field to shield us from Jupiter’s radiations. The atmosphere and the climate needs some fine tuning though. Once that is done, Europa can be colonised.