Looking for planetary systems beyond the solar system is another direction for exploring extraterrestrial civilizations. ——Carl Sagan

The exploration of extraterrestrial civilizations is not only part of the exploration of the universe, but will also have a profound impact on human evolution and the development of science and technology. ——Zhou Haizhong

SETI explores signals of various spectrums in the universe, hoping to discover intentional or unintentional broadcasts from extraterrestrial civilizations. The probability of success for such a project is difficult to determine. ——Seth Shostak

It has become increasingly difficult to raise funds for the search for extraterrestrial intelligence in recent years. As the economic recession continues, we have to adjust the timetable for the expected discovery of extraterrestrial intelligence. Postpone backwards.

——Frank Drake