Harpalyke, also known as Jupiter XXII, is a retrograde irregular-shaped satellite belonging to the outer planet of Jupiter. This satellite was discovered by Eugene A. Magnier, Yanga R. Fernandez, Scott S. Sheppard, and David C. Jewett on November 23, 2000 at the Mauna Kea Observatory. It belongs to the Ananke group, with Ananke being the largest in the group. Harpalyke takes about 620 Earth days to orbit Jupiter once.
Since it is part of the Ananke group, it was formed from the remains of the formation of the Ananke group. Ananke was a stray asteroid from the Asteroid belt pulled in by Jupiter's gravitational pull. Ananke then suffered numerous collisions. The left over debris became the satellites of the Ananke group, with the largest being Ananke.
All of the satellites in the Ananke group have colder atmospheres or poles than other satellites belonging to Jupiter. Harpalyke has many patches of snow and ice on the surface of this satellite, because the direction it orbits Jupiter in. Only one side of the moon faces the Sun at any one given time, such as Earth's Moon.