S/2004 (45) 1

S/2004 (45) 1 is one of the two known moons orbiting the asteroid 45 Eugenia. Discovered in March 2004 by a team led by Franck Marchis using observations from the Keck Observatory in Hawaii, it is the smaller of the two moons accompanying 45 Eugenia. This moon's discovery was significant in that it added to our understanding of the complex satellite system around asteroids. S/2004 (45) 1 is comparatively smaller in size, estimated to have a diameter of approximately 6 kilometers, making it significantly smaller than its sibling moon, Petit-Prince. The orbits of both moons, Petit-Prince and S/2004 (45) 1, around 45 Eugenia are relatively well-determined. These orbits help astronomers understand the gravitational interactions and stability within the asteroid-moon system. These interactions can provide information on the mass and density of the main asteroid as well as the formation mechanisms that led to the creation of its satellite system.