Extraterrestrial Life
The Rio Scale
A scale that measures the significance of potential contact with extraterrestrial intelligence
Type 1 Civilization
A type 1 civilization on the Kardashev scale is one able to harvest all the light hitting their planet from the neighboring star
Type 2 Civilization
A type 2 civilization on the Kardashev scale is one able to harvest all the light from their parent planet. Popular theories include Dyson's sphere and Dyson's swarm
Type 3 Civilization
A type 3 civilization on the Kardashev scale is one able to harness all the energy of the host Galaxy. It is often speculated that they would colonize sustainable planets in nearby star systems, and crush any developing life
The Drake Equation
An equation that predicts the density of alien life in a given galaxy.
Extraterrestrial Life
Life found anywhere besides Earth, ranging from microbes, to multicellular beings, to space faring civilizations
Extraterrestrial Intelligent
Life found anywhere besides Earth, that is advanced enough to have a form of consciousness, a well develop society, and language
SETI
SETI (Search for Extraterrestrial Intelligence) is an organization searching for radio signals from any advanced alien life
The Fermi Paradox
The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates, such as in Drake equation, of the probability of the existence of extraterrestrial life civilizations and the lack of contact with, or evidence for, such civilizations.
The Kardashev Scale
The Kardashev scale is a method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to use for communication.