The search by scientists of several nations for some sign of intelligent life on other worlds. Some believe that intelligent life exists on other planets. With an estimated 400 billion stars in our own galaxy and a guess (based on present theories of star formation) that a tenth of them may have planets one per system of which may prove suitable for life analogous to that on Earth there is a very high possibility that there is life elsewhere in our galaxy alone. If we speculate that one in 10,000 of such planets might go on to develop intelligent life that is capable of communicating between the stars, and should they last long enough for a reasonable proportion to be communicating, then it is worth looking for interstellar communications by electromagnetic radiation by radio transmission. This calculation is controversial because it compounds a number of plausible speculations into an extreme extrapolation of current thinking. Nevertheless, several scientists, including Carl SAGAN, thought that there was a sufficient possibility to be worth exploring. Sagan drew up a petition, which was signed by 72 prominent scientists from 14 countries, calling for a search to be funded. Congress in 1982 allocated $1.5 million to NASA to begin a long-term search for signals from extraterrestrial beings.