The land mass of Earth is mostly made of 32% iron, 30% oxygen, 15% silicon, 14% magnesium, 3% sulfur and 2% nickel. The remaining 4% is made up of much smaller piles of calcium, aluminum, and other trace elements.
There are many factors that make life possible on Earth.
- Earth's distance from the Sun makes the Earth a comfortable temperature for life to exists. Any closer to the Sun and it would be far to hot like Venus,
and further away and it would be to cold like Mars.
- Water covers over 70% of the Earth's surface. Without liquid water on Earth, life simply would not exist. I say liquid water because there is water on other planets such as Mars, but the water on Mars is restricted to its
polar ice caps. For life to exist, there needs to be liquid water.
- Earth's atmosphere is made mostly of nitrogen and oxygen (78% and 21% respectively). This combination of gases along with Earth's strong magnetic field protects us from all of the harmful rays from the Sun.
Take a look at the illustration below courtesy of UniverseToday.com. It clearly shows how Earth's magnetic field keeps the Sun's rays at bay:
Earth atmosphere acts as a heat shield during the daytime and a heat trap at night. Without it the temperatures during the day and night would move between the extremes of hot and cold making life very, very difficult.
Earth's atmosphere also provides us with air to breath. Obviously, without air there would be no life on Earth.
Diameter: 12,800 km
Earth Day: 24 hours
Orbits the Sun every 365 days (1 year)
Earth orbits the Sun at a speed of 107,870 km per hour or 67,027 miles per hour.
Average Distance from Sun: 93 million miles
Atmosphere: Mainly nitrogen 78.084% Nitrogen, 20.946% Oxygen. The remaining includes small amounts of Argon, Carbon Dioxide, Helium, Hydrogen, Methane.
Natural Satellites: 1 - the Moon
Average distance from Earth to Moon is 384000km or 238607 miles. The Moon orbits Earth in 27.32 days.
71% of the Earth's surface is covered in water.
Temperature Range: -69°C to 58°C.
Earth is more than 4.5 billion years old.
