Extraterrestrial life

Definition and Hypotheses

Extraterrestrial life refers to life that may exist and originate outside the planet Earth, the only place in the universe currently known to harbor life. The nature of extraterrestrial life, if it exists, remains a topic of conjecture and hypotheses. These range from "simple" microorganisms to beings with civilizations far more advanced than that of humans.

Astrobiology

Astrobiology is the interdisciplinary science that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology considers the question of whether extraterrestrial life exists, and if it does, how humans can detect it.

Hypothetical Types of Biochemistry

All life on Earth is based on carbon and water, but some researchers have speculated about alternative biochemistries. The most popular alternative is silicon-based life, which could occur in a non-water solvent.

Potential Habitability

The concept of "habitability" in astrobiology refers to the potential of an extraterrestrial body to support life as we know it. While Earth is currently the only known location able to support life, scientists speculate that other bodies in our solar system, such as Mars or the moons of Jupiter and Saturn, could potentially harbor life.

Search for Extraterrestrial Life

The search for extraterrestrial life encompasses many fundamental scientific questions. What are the basic requirements for life? Could life exist elsewhere in the universe? What forms could alien life take? And, would such life be intelligent or have the ability to communicate with us?

Fermi Paradox

The Fermi Paradox is the apparent contradiction between high estimates of the probability of extraterrestrial life and the lack of evidence or contact with such civilizations.

Drake Equation

The Drake Equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.

Cultural Impact

The potential existence of extraterrestrial life has had a significant impact on science fiction and popular culture. The idea of intelligent life has also sparked philosophical and religious discussions about humanity's place in the universe.