100 Facts About Earth

100 Facts About Earth

Here’s a full, categorized list covering Earth’s structure, atmosphere, life, history, and cosmic context.

1. Basic Facts (1–10)

Earth is the third planet from the Sun.
It’s the only known planet to support life.
Earth formed about 4.54 billion years ago.
The name “Earth” comes from Old English and Germanic words meaning “ground.”
Earth is roughly 12,742 km (7,918 miles) in diameter.
It has a circumference of about 40,075 km (24,901 miles) at the equator.
The planet’s total surface area is 510 million km², with 71% covered by water.
Earth’s mass is approximately 5.97 × 10²⁴ kilograms.
Earth orbits the Sun at an average distance of 149.6 million km (93 million miles).
It takes 365.25 days to complete one orbit around the Sun — our year.

2. Orbit, Motion & Time (11–20)

Earth rotates once every 23 hours, 56 minutes, and 4 seconds — a sidereal day.
The planet rotates from west to east, making the Sun appear to rise in the east.
Earth’s tilt is 23.5°, which causes the seasons.
The equatorial rotation speed is about 1,670 km/h (1,037 mph).
Earth’s orbit is elliptical, not perfectly circular.
The perihelion (closest to the Sun) occurs in early January.
The aphelion (farthest from the Sun) occurs in early July.
A leap year adds an extra day every four years to correct for the 0.25-day difference.
Earth’s axial precession slowly changes the orientation of its axis every 26,000 years.
The Moon stabilizes Earth’s tilt, preventing extreme climate swings.

3. Internal Structure (21–30)

Earth has three main layers: crust, mantle, and core.
The crust is the thin, outermost layer, 5–70 km thick.
The mantle makes up about 84% of Earth’s volume.
The outer core is liquid iron and nickel.
The inner core is solid, mostly iron and nickel, with a temperature near 5,400°C (9,800°F).
The core’s heat drives plate tectonics.
The movement of molten metals in the outer core generates Earth’s magnetic field.
The crust is divided into tectonic plates that float on the semi-fluid mantle.
There are 7 major plates and numerous smaller ones.
Earthquakes occur at plate boundaries where plates move or collide.

4. Atmosphere (31–40)

Earth’s atmosphere extends up to about 10,000 km (6,200 miles), though it thins rapidly.
The atmosphere is 78% nitrogen, 21% oxygen, and 1% other gases.
The troposphere is the lowest layer, where weather occurs.
The stratosphere contains the ozone layer, which absorbs harmful UV rays.
The mesosphere burns up most meteors.
The thermosphere hosts auroras and the International Space Station.
The exosphere gradually fades into outer space.
Air pressure at sea level is about 1013 millibars (1 atm).
The ozone layer protects life from ultraviolet radiation.
Human activity has affected atmospheric composition, leading to climate change.

5. Water & Oceans (41–50)

Earth is often called the Blue Planet because of its oceans.
Oceans cover 71% of the surface and contain 97% of all water.
The Pacific Ocean is the largest, covering 63 million square miles.
The Mariana Trench is the deepest point at 10,984 meters (36,037 feet).
Only about 3% of Earth’s water is fresh, and most of it is frozen.
The hydrologic cycle moves water through evaporation, condensation, and precipitation.
Ocean currents distribute heat and regulate climate.
The Gulf Stream warms Western Europe.
Phytoplankton in oceans produce most of Earth’s oxygen.
The oceans absorb about 25% of human CO₂ emissions, helping balance the atmosphere.

6. Land & Geology (51–60)

Continents cover about 29% of Earth’s surface.
The highest point is Mount Everest (8,848 m / 29,032 ft).
The lowest land point is the Dead Sea Depression (-430 m / -1,410 ft).
The largest continent is Asia, the smallest is Australia.
The largest desert is Antarctica, followed by the Sahara.
Earth’s crust is constantly recycled by plate tectonics.
The Ring of Fire around the Pacific hosts 75% of Earth’s volcanoes.
There are over 1,500 active volcanoes worldwide.
The supercontinent Pangaea existed about 335 million years ago.
Continents drift about 2–5 cm per year due to tectonic motion.

7. Life & Biosphere (61–70)

Earth is the only known planet with life.
Life began at least 3.8 billion years ago.
There are an estimated 8.7 million species on Earth.
About 80% of all life lives in the ocean.
The Amazon Rainforest produces 20% of Earth’s oxygen.
Microorganisms make up most of Earth’s biomass.
The biosphere includes all regions where life exists — land, water, and air.
Coral reefs are among the most diverse ecosystems on Earth.
Earth’s atmosphere and liquid water make it uniquely habitable.
Humans have discovered only about 15% of all species.

8. Geography & Natural Phenomena (71–80)

The equator divides Earth into Northern and Southern Hemispheres.
The prime meridian divides it into Eastern and Western Hemispheres.
Gravity varies slightly across the surface due to density differences.
The Challenger Deep is the lowest point on Earth’s crust.
Tides are caused by the Moon’s gravitational pull.
The Coriolis effect influences weather patterns and ocean currents.
Auroras occur when solar particles hit Earth’s magnetic field.
Earth’s magnetic poles wander and can even reverse.
The Ring of Fire is responsible for 90% of the world’s earthquakes.
The largest earthquake ever recorded was magnitude 9.5 (Chile, 1960).

9. Humans & Civilization (81–90)

Humans have existed for about 300,000 years.
The global population surpassed 8 billion in 2022.
There are over 190 countries on Earth.
The most populous country is India, followed by China.
The tallest human-made structure is the Burj Khalifa (828 m).
Agriculture began about 10,000 years ago, leading to civilizations.
Humans have altered over 75% of Earth’s land surface.
Deforestation, pollution, and climate change threaten ecosystems.
Renewable energy use is increasing to reduce carbon emissions.
Satellites constantly monitor Earth’s weather, land, and oceans.

10. Cosmic Context & Future (91–100)

Earth orbits within the habitable zone of the Sun.
The planet’s average surface temperature is 15°C (59°F).
The Moon formed after a giant impact about 4.5 billion years ago.
The Moon’s gravity causes tides and stabilizes Earth’s tilt.
Earth is part of the Solar System, inside the Milky Way Galaxy.
The Solar System orbits the galactic center every ~230 million years.
Earth’s magnetic field protects us from solar wind and cosmic radiation.
Human activity is now changing Earth’s climate faster than ever before.
Terraforming ideas imagine making other planets Earth-like — but none are yet viable.
If viewed from space, Earth shines as a pale blue dot — a fragile oasis in the vast universe.

Earth is dynamic, living, and interconnected — a planet shaped by cosmic forces, geology, and life itself. It’s the only known world that harbors liquid water, breathable air, and complex ecosystems, making it uniquely precious in the cosmos.