Herse ( /ˈhɜrsiː/ HUR-see; Greek: Ἕρση), or Jupiter L, previously known by its provisional designation of S/2003 J 17, is a natural satellite of Jupiter. It was discovered on 8 February 2003 by the astronomers Brett J. Gladman, John J. Kavelaars, Jean-Marc Petit, and Lynne Allen. It was named after Herse 'dew', a daughter of Zeus and Selene the moon in Greek mythology, on 11 November 2009.
Herse is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 22,134 Mm in 672.752 days, at a mean inclination of 165° to the ecliptic, in a retrograde direction and with a mean eccentricity of 0.2493.
It is the innermost member of the Carme group, made up of irregular retrograde moons orbiting Jupiter at a distance ranging between 23 and 24 Gm and at an inclination of about 165°.