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
Surface-to-air missile than aircraft. Virtually all surface warships can be armed with SAMs, and naval SAMs are a necessity for all front-line surface warships. Some warship types specialize in anti-air warfare e.g. "Ticonderoga"-class cruisers equipped with the Aegis combat system or "Kirov" class cruisers with the S-300PMU "Favorite" missile system. Modern Warships may carry all three types (from long-range to short-range) of SAMs as a part of their multi-layered air defence. SAM systems generally fall into two broad groups based on their guidance systems, those using radar and those using some other means. Longer range missiles generally use radar for early detection