691 Lehigh is an asteroid orbiting the Sun in the asteroid belt, discovered in 1909.
[3] It is named after Lehigh University, where its orbit was calculated in the Masters Thesis of Joseph B. Reynolds, following the observations of amateur astronomer Joel Metcalf.
The asteroid is a CD:-type asteroid, suggesting its surface is largely carbonaceous, with many primitive molecules similar to those of comets.
Due to this, it has a cometlike surface albedo 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 collisional asteroid family.