Harpalyke belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.[8][9] It is about 4 kilometres in diameter[10] and appears grey (color index R-V=0.43), similar to C-type asteroids.[11] The satellite orbits Jupiter at an average distance of 21,064,000 km in 634.19 days, at an inclination of 147° to the ecliptic (147° to Jupiter's equator) with an eccentricity of 0.2441.
^Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
^Sheppard, S. S.; Jewitt, D. C.; and Porco, C. C.; Jupiter's Outer Satellites and Trojans, in Jupiter: The Planet, Satellites and Magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, and William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN0-521-81808-7, 2004, pp. 263-280