Jupiter's moon Europa (Europa) is considered the most promising place in the solar system to host alien life. There are oceans of liquid water tens of kilometers deep. This water may have interfaced with the soil on the ocean floor, providing the necessary chemicals for life to arise.
Unfortunately, the surface of Europa is covered with a thick layer of ice, the temperature of the ice layer is around -26 ° C, and the ocean is tightly hidden under the ice layer, at least 5 kilometers above the surface. Drilling to such depths to find life, not to mention on alien planets, is a serious challenge on Earth.
Fortunately, not all of the liquid water on Europa is buried this deep. According to images taken by NASA's Galileo spacecraft, there are places in Europa's surface ice that appear to be dark. Scientists speculate that there is likely liquid water there. Because water is less reflective than ice, it appears darker.
There are hundreds of such places, each with a diameter of more than 10 kilometers. It can be said that they are lakes under the ice. This liquid water may have infiltrated cracked ice shells from subsurface oceans, or the ice shells may have been partially melted by external influences (such as solar flares, cosmic rays), and then the ice surface refreezes.
This water is in sub-zero ice without freezing, possibly because of its salt content. Water, which is high in salt, also has a low freezing point, so it remains liquid at sub-zero temperatures. According to simulations, this water can exist for tens of thousands of years before refreezing.
These subglacial lakes could be potential habitats for life. For example, if life exists in the subsurface ocean, it should thrive in subglacial lakes as it seeps into the ice shell with seawater. Subglacial lakes are closer to the surface, perhaps only a kilometer deep, and are much easier to drill than subglacial oceans.
NASA's Europa Clipper spacecraft is scheduled to launch in 2024 and arrive in 2030. At that point, the spacecraft will skim over Europa and use radar to peek beneath its ice. It also comes with a dust analyzer that can detect material from these subterranean lakes — possibly even the microbes themselves.
If these lakes do exist, humans will launch landers to Europa in the future to drill directly through the ice for sampling.
.jpeg)