Albedo objects in the outer Solar System and asteroid belt have low albedos down to about 0.05. A typical comet nucleus has an albedo of 0.04. Such a dark surface is thought to be indicative of a primitive and heavily space weathered surface containing some organic compounds. The overall albedo of the Moon is measured to be around 0.136, but it is strongly directional and non-Lambertian, displaying also a strong opposition effect. Although such reflectance properties are different from those of any terrestrial terrains, they are typical of the regolith surfaces of airless Solar System bodies. Two common albedos that are
Riemannian connection on a surface Riemannian connection on a surface embedded in Euclidean space "E" is just the pullback under the Gauss map of the Riemannian connection on "S". Using the identification of "S" with the homogeneous space SO(3)/SO(2), the connection 1-form is just a component of the Maurer–Cartan 1-form on SO(3). In other words, everything reduces to understanding the 2-sphere properly. For a surface "M" embedded in E (or more generally a higher-dimensional Euclidean space), there are several equivalent definitions of a vector field "X" on "M": The last condition means that the assignment "f" "Xf" on "C"("M") satisfies the Leibniz rule The space