Defining 'Alien Life'
Alien life refers to any life form not from Earth. This broad definition includes microorganisms and extends to potentially more complex beings.
The Drake Equation
Devised by Frank Drake, this equation estimates the number of communicative civilizations in our galaxy, considering factors like star formation and planets' potential for life.
Exoplanets and Habitability
Thousands of exoplanets have been discovered with many in the 'habitable zone' where liquid water could exist. This raises the possibility of Earth-like conditions for life.
Extremophiles on Earth
Life exists in Earth's extreme environments, such as deep-sea vents and acidic springs. These extremophiles suggest life's potential to thrive in harsh alien worlds.
Panspermia Hypothesis
Panspermia suggests that life exists throughout the Universe, distributed by space dust, meteoroids, asteroids, comets, planetoids, or potentially by spacecraft, in the form of unintended contamination by microorganisms.
SETI and METI Efforts
SETI (Search for Extraterrestrial Intelligence) and METI (Messaging to Extraterrestrial Intelligence) are scientific efforts aimed at finding and communicating with alien civilizations through radio signals and other methods.
Unexplained Phenomena
UFO sightings and other unexplained phenomena often spark interest in alien life. While most cases have earthly explanations, some incidents remain unidentified, fueling speculation and further study.
Alien DNA on Earth?
Some scientists believe extremophiles' resilience might indicate traces of alien DNA, suggesting that life on Earth could have extraterrestrial origins.