Earth and Life Science: Origin and Structure of Earth

This set covers the fundamental concepts of Earth's habitability, its five essential survival factors, and the four major subsystems (Atmosphere, Geosphere, Hydrosphere, and Biosphere) as presented in Modules 1 and 2.

Earth & Life Science

A field that presents the history of the Earth through geologic time, discussing structure, composition, processes, natural hazards, and basic principles of biology.

Habitable Zone

The region around a star where conditions are neither too hot nor too cold, typically occupied by planets with sizes $1 \times$ to $2 \times$ that of Earth.

Temperature range for life

The ideal temperature interval to support life, which is between $-15^\text{o}C$ to $115.96$.

Water

An essential factor for all life forms on a planet.

Atmosphere (Habitability factor)

A thick gaseous layer required to protect life and insulate the planet.

Energy

Input from the Sun or chemical sources used to run chemical processes necessary for life.

Nutrients

Chemicals necessary to make proteins and other essential biological components.

Atmosphere (Subsystem)

The gaseous layer above the Earth's surface composed of $78\%$ nitrogen, $21\%$ oxygen, and $1\%$ other gases.

Geosphere

The subsystem including all rocks that make up Earth, from the core, mantle, and crust to grains of sand and mountains.

Hydrosphere

The subsystem comprising all water on the surface, underground, and in the air in liquid, vapor, or ice forms.

Biosphere

The subsystem consisting of parts of Earth where life exists, overlapping the atmosphere, geosphere, and hydrosphere.

Nitrogen

The primary gas in Earth's atmosphere, making up approximately $78\%$ of its composition.

Oxygen

A gas making up approximately $21\%$ of the atmosphere, provided for animals to support life.

Carbon Dioxide

A gas found in the atmosphere that is used by plants to support life.

Mid-2009 Earth Population

A point in time when the human population reached $6.7$ billion people.