If Astrosociobiology is going to become a serious science, means need to be found to make contact with extraterrestrial civilizations. So far, the major approach to detecting or possibly communicating with extraterrestrial civilizations is the use of radio telescopes to detect electromagnetic signals from outer space (SETI).
Most SETI efforts assume that advanced extraterrestrial civilizations might attempt to send powerful radio signals into space that a relatively primitive technological society (such as our own) might be able to detect. However, it may be that the "Radio Age" is very short for most civilizations, and few radio signals may exist in our galaxy. Also, it may be that advanced extraterrestrial civilizations attempt to hide from primitive cultures, in order to prevent contaminating them or otherwise interfering with their natural course of development. If so, new means of detecting extraterrestrial civilizations may be needed.