Earth's Characteristics and Subsystems

Essential components of Earth drive the existence of life, including plants, animals, and microorganisms.
Earth's unique presence of liquid water covers approximately 75% of its surface, essential for sustaining life.
Water exists in various forms: atmosphere, ground, freshwater bodies, and polar ice caps, and is critical for biological processes.
Plant composition can be up to 90–95% water by weight, while adult humans are around 60% water.

Earth is described as having "Goldilocks" conditions, making it "just right" for life by being neither too hot nor too cold.
Located third from the Sun, Earth maintains a temperature range from –88°C to 58°C, allowing liquid water to exist.
Gravitational force retains most gases close to the surface, forming an atmosphere about 21% oxygen, crucial for respiration.

Earth's atmosphere traps heat, protecting living organisms from the Sun's harmful rays.
The Moon influences tides and plays a role in the navigation and migration patterns of certain species, affecting the distribution of life.

Temperature: Organisms thrive within a temperature range of -15°C to 115°C, with H2O remaining in liquid form essential for life.
Water: Vital for dissolving and transporting nutrients and materials in cellular processes; Earth's unique chemical makeup supports liquid water.
Right Atmospheric Conditions: The atmosphere traps heat, maintains the greenhouse effect, and protects against radiation via the ozone layer, spanning about 100 miles in thickness.
Energy Supply: The Sun serves as the primary energy source for living organisms, powering essential biological processes.