691 Lehigh is an asteroid orbiting theSun in the asteroid belt, discovered in 1909.[3] It is named afterLehigh University, where its orbit was calculated in the Masters Thesis of Joseph B. Reynolds, following the observations of amateur astronomerJoel Metcalf. The asteroid is aCD:-type asteroid, suggesting its surface is largely carbonaceous, with many primitive molecules similar to those of comets. Due to this, it has a cometlike surfacealbedo of just 0.05, similar to fresh asphalt, meaning that it reflects only 5% of light that hits it. Lehigh is not known to be a member of any collisionalasteroid family.