Life on Other Worlds

Flashcards covering vocabulary and important concepts from the lecture on life in the universe.

Life

A challenging concept to define, characterized by properties such as energy acquisition, self-maintenance, adaptation, information storage, and reproduction.

DNA

Deoxyribonucleic acid, a molecule that contains the genetic instructions for the development and function of living organisms.

Mutation

Random alterations to DNA that can result in changes in an organism, with some mutations being beneficial, while others can be fatal.

Natural Selection

The process through which evolutionary changes occur based on the differential survival and reproduction of organisms due to their traits.

Primordial Soup

A theoretical mixture of organic compounds in Earth's early oceans, believed to be crucial for the origin of life.

Cambrian Explosion

A significant event in Earth's history, around 540 million years ago, marked by a rapid increase in the diversity of life forms.

Extremophiles

Microorganisms that thrive in extreme environmental conditions, providing insight into the possibilities of life beyond Earth.

Fermi Paradox

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

Drake Equation

A formula used to estimate the number of active extraterrestrial civilizations in the Milky Way galaxy that can communicate with us.

Astrobiology

The study of life in the universe, including the origins, evolution, distribution, and future of life on Earth and beyond.

Astrobiological Signatures

Indicators or markers that may suggest the presence of life in astronomical observations.

Ozone Layer

A protective layer of ozone (O3) in Earth's atmosphere that absorbs most of the Sun's harmful ultraviolet radiation.

Exoplanets

Planets that orbit a star outside our solar system, many of which may be located in the habitable zone where conditions can support life.

SETI (Search for Extraterrestrial Intelligence)

An exploratory science that seeks evidence of life in the universe by looking for signs of intelligent life.

Organic Molecules

Complex compounds containing carbon that are the building blocks of life, detected in various cosmic locations.

Galactic Habitable Zone

The region in a galaxy where conditions may be suitable for life to exist, influenced by factors such as star density and metallicity.

Heavy Elements

Elements that are essential for life but are produced in stars and supernovae, crucial for the development of planets like Earth.