The Possibility of Liquid Water on Planets Outside of the Habitable Zone

Being in the habitable zone doesn't always mean that a planet has liquid water on it. The universe gets creative with finding ways to heat a planet, so it is actually possible to find water outside of the habitable zone under certain conditions. For example, people talk about some of the moons of Saturn, like Titan and Europa,. These could have oceans of liquid water beneath their surfaces despite being way outside our solar system's habitable zone.