Astrobiology is the scientific study of the origin, evolution, distribution, and future of life in the universe.

The SETI Institute is a non-profit organization dedicated to the search for extraterrestrial intelligence.

The Allen Telescope Array is a radio telescope array located in northern California, USA.

The Arecibo Message was a radio message sent from the Arecibo Observatory in Puerto Rico to the globular cluster M13.

Voyager 1 is a space probe launched by NASA in 1977.

The Pioneer Plaque is a metal plaque attached to the Pioneer 10 and Pioneer 11 spacecraft.

SETI@home is a distributed computing project that searches for extraterrestrial signals.

The Kardashev Scale is a method of measuring the technological advancement of a civilization.

The Drake Equation is an equation that attempts to estimate the number of extraterrestrial civilizations in the Milky Way galaxy.

The Fermi Paradox is a paradox that questions why we have not yet detected any extraterrestrial civilizations.

The SETI Paradox is a paradox that questions why we have not yet been contacted by an extraterrestrial civilization.

The Outer Space Treaty is an international treaty that governs the exploration and use of outer space.

The Outer Space Treaty states that extraterrestrial life is the common heritage of mankind.

The Outer Space Treaty states that astronauts must respect the rights of other astronauts, avoid contact with extraterrestrial life, and not interfere with the natural environment of a celestial body.