Earth's Formation and Characteristics

Earth's Formation and Characteristics

• Earth formed approximately 4.5 billion years ago, alongside other solar system bodies.
• Earth is the fifth-largest planet in the solar system.
• Its diameter is roughly 8,000 miles.
• Earth is the third planet from the sun, at an average distance of 93 million miles.
• Earth is sometimes called the "Goldilocks planet" because conditions are just right for life.
• It has liquid water, essential for life.
• Earth is the only known planet with abundant liquid water.

Earth's Appearance from Space

• From space, Earth appears like a blue marble.
• The blue areas represent water (covering about 71% of Earth's surface).
• White areas are clouds, ice, and snow.
• Brown, yellow, and green areas represent landmasses.

Earth's Hemispheres and Poles

• An imaginary line called the equator divides Earth into two halves: the Northern and Southern Hemispheres.
• The northernmost point is the North Pole.
• The southernmost point is the South Pole.

Earth's Movement and Day/Night Cycle

• Earth orbits the sun once every 365 days.
• Earth's orbit is not a perfect circle but slightly oval.
• Its distance from the sun varies throughout the year.
• Earth rotates on its axis once every 24 hours, creating day and night.
• Earth's axis is tilted at 23.5 degrees, which causes seasons.

Earth's Seasons

• The tilt of Earth's axis causes the sun's rays to hit different parts of the planet more directly at different times of the year.
• This uneven heating results in the changing seasons.

Earth's Composition and Internal Structure

• Earth consists of land, air, water, and life.
• Earth's atmosphere is primarily nitrogen and oxygen.
• Earth's internal structure includes layers of rock and metal, with temperatures increasing toward the core.
• The Earth's surface layers have mountains, valleys, plains, and other landforms.

NASA's Study of Earth

• NASA studies changes affecting Earth (natural and human-caused).
• This includes tracking weather patterns, climate change, diseases, and natural disasters.
• NASA uses satellites to collect information about Earth's different components.
• Analyzing this data allows scientists to predict future changes and improve decision-making.