If there is hope for String Theory to be validated through accepted experimentation in the near future, it will be in the depths of black holes. One of the most dramatic recent events in String Theory was the derivation of the Bekenstein-Hawking entropy formula for black holes, which is obtained by counting microscopic string states which form a black hole. The entropy of a black hole is written as S=A/4, where A is the area of the event horizon around a black hole (an orbiting ring of debris that is caught just inside the gravitational pull of a black hole). Strominger and Vafa found that this formula can be derived by counting the degeneracy of quantum states of string configurations and the D-branes which correspond to certain supersymmetric black holes in string theory. In effect, these D-branes provide a short distance (very very short distance) weak coupling description of certain black holes (although certainly not all of them). Hawking radiation, the observable phenomenon of particles “emitted” by a black hole when pair production occurs just inside the event horizon (one is sucked in and the other kicked out), can also be understood in terms of open strings traveling in both directions. When these open strings interact (and their worldsheets merge), radiation is emitted in the form of closed strings. As a result of this development, many string theorists have their sights fixed on the sky.