One of the oldest questions that humanity is still yet to answer, is whether or not we are alone in the universe. The sheer size of just the known universe and the number of potentially habitable worlds we’ve already found points towards the existence of life outside of our planet. But if it exists, it’s yet to present itself to us. For decades, we’ve been searching the depths of the universe for any clues of other civilizations or even microbial life. But the search has also continued much closer to home in our own star system. 

   One moon that has caught the attention of many scientists is Europa. In the quest to find life, it seems like Europa may hold some of the best chances in our solar system. 

   Europa is the smallest of the four Galilean moons of Jupiter (the others are Io, Ganymede, and Callisto). The surface of Europa is completely frozen, but many believe that a vast ocean, perhaps containing more water than Earth, exists below the surface. This characteristic surprised many people since Europa was so far away from the sun. Liquid water should not be able to stay liquid at that distance. However, Jupiter’s massive gravitational pull essentially pulls and stretches the moon as it orbits the Jovian world. When this happens, friction is created, and scientists believe that the heat generated by this friction might be enough to allow liquid water to survive below the surface. Water was the building block of life on Earth, so many scientists believe that life may have evolved or be evolving in the watery depths of the moon’s ocean. 

   To better understand the moon itself, a new mission, Europa Clipper, will orbit and conduct over 45 flybys of Europa. The mission is tasked with determining whether or not Europa is capable of sustaining life. It will give scientists a better understanding of the surface of the Jovian moon and unravel the secrets locked under the icy surface. The mission will give scientists a better understanding of how deep this ocean may be and how thick the ice crust of the moon is. 

   The Europa Clipper mission is equipped with a host of different instruments that will transmit a wide range of data back to Earth. 

Cameras – 

   The mission is set to carry multiple different types of cameras. The first is the Europa Imaging System (EIS) that will produce images that will reveal the geologic activity of the moon. This is important because the surface of Europa is relatively young, especially when compared to the age of the moon itself. 

   The Europa Thermal Emission Imaging System (E-THEMIS) will make use of the infrared part of the light spectrum to spot the warmer parts of the surface where warm liquid water may be present. This camera will also reveal the smaller details of the surface that will further our understanding of the history of the moon. 

Radar and Gravity – 

   A gravity experiment will be conducted by the mission to determine exactly how Jupiter’s gravity affects the moon. In the experiment, antennas on Earth will send a radio signal to Europa Clipper and the orbiter will return the signal at the frequency that it was received at. The teams on Earth will then analyze the Doppler shift and other properties of the signal to understand the gravity shifts around Europa. The gravity field mirrors the shape of the moon itself, so understanding how the gravity field changes will allow scientists to directly understand exactly how the moon is being stretched by Jupiter. 

Chemical Analysis – 

   The Surface Dust Mass Analyzer (SUDA) will study the surface chemistry of Europa. Most moons, including our own, are constantly blasted with micrometeorites which can eject surface material. Scientists believe that around 500kg (half a ton) of this material is simply floating around the planet. 

   SUDA will collect these particles and pass them through a gridlike structure that will identify the speed of the particle and its trajectory so the pieces can be traced back to their origin point on the surface. After, the particles will be thrown against a metal plate, which will separate them into their individual molecules. Then, some of these molecules will be ionized (electrically charged). These ionized particles will be passed to a detector, where a mass to charge ratio will determine the amount of time it takes the molecule to collide with it. This time can be used to determine the mass and composition of the particle. Through this process, scientists can understand the surface composition of Europa with only an orbiter mission!

   If life does indeed exist in the waters of Europa, it will likely be very different from us. For one thing, the life there would have evolved under difference circumstances, including a different gravity, and different temperatures. Even if the life turned out to simply be microbial, it would be a revolutionary step forward for the scientific community. 

   Of course the possibility still exists that Europa may be covered in water, but still contain no life. Even if that was the case, the moon is still extraordinary and there is much we still can learn from exploring an ocean on another world.