In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.[37] In September 2008, Franck Marchis and his collaborators announced that by using the Keck Observatory's adaptive optics system, they had discovered two moons orbiting Kleopatra.[38] The outer and inner satellites are about 8.9 ± 1.6 and 6.9 ± 1.6 km in diameter, with periods of 2.32 ± 0.02 and 1.24 ± 0.02 days, respectively.[39][40]