117138

117138 is a minor planet in the outer region of the asteroid belt, orbiting the Sun between Mars and Jupiter. It was discovered on September 11, 2004, by astronomers at the Palomar Observatory in California. The asteroid is part of the Eos family, a group of asteroids that share similar orbital elements and spectral characteristics.

117138 has an estimated diameter of approximately 10 kilometers. Its orbit has a semi-major axis of about 3.1 astronomical units (AU), with an eccentricity of 0.15 and an inclination of 10.5 degrees relative to the ecliptic plane. The asteroid completes one orbit around the Sun in about 5.5 Earth years.

The spectral classification of 117138 is S-type, indicating that it has a stony composition. This classification is based on its reflectance spectrum, which shows absorption features typical of silicate minerals. The surface of 117138 is likely composed of olivine and pyroxene, common minerals found in stony meteorites.

The asteroid's rotation period is approximately 6.5 hours, and its light curve indicates a relatively spherical shape. The albedo, or reflectivity, of 117138 is estimated to be around 0.2, which is typical for S-type asteroids.

117138 is not a target for any specific missions or studies, but it is part of ongoing research into the composition and dynamics of the asteroid belt. Its discovery and characterization contribute to our understanding of the early solar system and the processes that shaped it.