At first glance, Saturn’s moon Enceladus doesn’t seem like a great place to live. Its entire surface is covered in ice, and temperatures hover at a bone-chilling -201°C (-330°F). It also has more than 100 active ice volcanoes, which blast a never-ending spray of ice, dust, and gases into the air.
Deep below Enceladus’s icy crust lies a totally different environment: a warm underground ocean (see Hidden Sea). Scientists have discovered that this vast sea has an abundance of organic molecules. These molecules contain the element carbon (C), which is the main building block for all living things on Earth. Researchers studying the ocean on Enceladus have also detected compounds that contain the elements hydrogen (H), nitrogen (N), oxygen (O), sulfur (S)—and, most recently, phosphorus (P).
Scientists consider these six elements essential for life as we know it. That’s led many researchers to believe Enceladus might be the best place to search for alien life in our solar system.