Albedo planet would drop to about 0 °C. In contrast, if the entire Earth was covered by water — a so-called aquaplanet — the average temperature on the planet would rise to almost 27 °C. For land surfaces, it has been shown that the albedo at a particular solar zenith angle "θ" can be approximated by the proportionate sum of two terms: the directional-hemispherical reflectance at that solar zenith angle, formula_1, and the bi-hemispherical reflectance, formula_2, with formula_3 being the proportion of direct radiation from a given solar angle, and formula_4 being the proportion of diffuse illumination. Hence, the actual albedo
Surface-to-surface missile bomb was the first operational surface-to-surface missile. Contemporary surface-to-surface missiles are usually guided. An unguided surface-to-surface missile is usually referred to as a rocket (for example, an RPG-7 or M72 LAW is an anti-tank rocket whereas a BGM-71 TOW or AT-2 Swatter is an anti-tank guided missile). Examples of surface-to-surface missile include the MGM-140 ATACMS, the Ground-Launched Small Diameter Bomb (GLSDB) and the Long Range Precision Fires (LRPF). Surface-to-surface missiles are usually broken down into a number of categories: Different parties break down missile type by the range differently. For example, the United States Department of Defense has no definition