The Drake Equation is a famous mathematical equation created by astronomer Frank Drake to estimate the number of communicative extraterrestrial civilizations in the Milky Way galaxy. However, there are several synonyms and related terms that are often used in the same context. These include the Fermi Paradox, which states that despite the high likelihood of the existence of extraterrestrial life, no concrete evidence has been found so far. Another term is the SETI program, which stands for the Search for Extraterrestrial Intelligence, an ongoing effort to detect signs of life beyond Earth. The Rare Earth Hypothesis is a related theory that argues that Earth-like planets are extremely rare, and therefore, the chances of finding intelligent life elsewhere are slim.