Illustration of the Jovian satellite Europa in the deep future. Around 6 billion years from now, the Sun will exhaust its hydrogen supply and swell into a red giant. At least two red giant phases are expected, with the Sun first ballooning to 160 times its current diameter, and then to around 180-200 times its current diameter. When this happens its luminosity will be so great that the icy satellites around the giant planets will begin to warm, their ice perhaps melting. Seen from Europa, the Sun could well surpass Jupiter in angular size in the sky. Io is shown off to the left in crescent phase.