If extraterrestrial life exists, it could range from simple microorganisms and multicellular organisms similar to animals or plants, to complex alien intelligences akin to humans. When scientists talk about extraterrestrial life, … See more

The first basic requirement for life is an environment with non-equilibrium thermodynamics, which means that the thermodynamic equilibrium must be broken by a source … See more

The science that searches and studies life in the universe, both on Earth and elsewhere, is called astrobiology. With the study of Earth's life, … See more

Although the idea of extraterrestrial peoples became feasible once astronomy developed enough to understand the nature of planets, … See more

It is unclear if life and intelligent life are ubiquitous in the cosmos or rare. The hypothesis of ubiquitous extraterrestrial life relies on three main … See more

The Solar System has a wide variety of planets, dwarf planets, and moons, and each one is studied for its potential to host life. Each one has its … See more

Cosmic pluralism
The modern concept of extraterrestrial life is based on assumptions that were not commonplace during the early days of astronomy. … See more