The picture is a hypothetical illustration of all the waters in the satellite Europa, which is in the form of a bubble, and that amount of water may be compared to the whole Europa in the area covered. Next to the picture, there is another hypothetical illustration of all the water on planet Earth compared to the whole mass of planet Earth. The picture illustrates a scale, therefore, making a clear comparison of the size of the Earth and Europa, and all their waters. Europa is one of the four largest moons found around the planet Jupiter. The other three are Lo, Ganymede, and Calisto. Europa is almost of the same size as the Earth’s moon, and it was discovered by the astronomer Galileo Galilei in 1610.
The surface of Europa is covered with ice and cracks as seen in the picture. Previous explorations show that beneath the ice covering its surface, separating the icy crust from the rocky interior, there is water, which creates an ocean. The ice floats on the water contacting with a rocky mantle, while in the earth, there is a crust. The cracks evident on its surface are made as a result of ocean tides underneath the ice which cause an eruption on the surface, the same way volcanic eruptions occur on Earth.
Europa is far from the Sun; hence, the ice covers the whole surface of that moon. Europa’s magnetic field reacts with that of Jupiter, proving the fact that the moon contains a liquid ocean underneath the layer of ice. Its orbiting around Jupiter is a source of heat in the interior of Europa, and this heat maintains the water in a liquid state despite the ice surface.
The picture also shows that the surface of the moon is relatively smooth and that Europa is much smaller than the Earth but has much more water than the Earth. Its water is almost twice as much as that on Earth. Although oceans usually make up most of the Earth’s surface, they are not as deep when compared to the depth of water on Europa’s surface. The waters and ice of Europa are several kilometers deep, and all the water in Europa makes up almost a quarter of its whole mass.
There are beliefs that the liquid ocean on the moon may support Extraterrestrial life. The Europa-Jupiter System Mission is to explore Jupiter and most importantly, Europa. Europa’s ocean is thought to be a few kilometers from the surface, and hence there is a likelihood of interaction between the ocean and the surface.