What makes Europa such an attractive place to look for life is the possibility that it has liquid water and volcanic activity.
Liquid water is essential for life on earth and is the most probable solvent for life elsewhere.
Volcanic activity provides some of the heat necessary to keep the water on Europa from freezing and could provide important dissolved chemicals needed by living organisms. The surface of Europa is covered with ice. NASA's Galileo space probe has recently sent back a number of high quality images of Europa's surface . These images hint at a layer of liquid water under the ice. We will probably have to wait for one or more additional missions to Jupiter and Europa to verify the presence of liquid water and life on Europa.