Mars has always been the top candidate for a planet other than Earth where life might be found in our own solar system.
But until recent findings/discovery that life "could" also be found in a moon. Yup, a moon, the Europa, a moon of the planet Jupiter. Europa is the fourth largest moon of Jupiter and the sixth largest moon in the solar system. Europa's surface is covered with ice (suggests water).
Right now, there is no other body in the solar system that attracts as much scientific attention as this bright strange-looking moon, the smallest of Jupiter's four large satellites.