Key Takeaways

  • Only known planet to support life, with 71% of its surface covered in liquid water
  • Located in the 'Goldilocks zone' - the perfect distance from the Sun for life
  • Protected by a magnetic field that shields us from harmful solar radiation

Table of Contents

What is the Earth Made of?

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.

Why is There Life on Earth?

There are many factors that make life possible on Earth. These unique conditions work together to create and sustain the incredible diversity of life we see today.

Distance from the Sun

Earth's distance from the Sun makes the Earth a comfortable temperature for life to exist. Any closer to the Sun and it would be far too hot like Venus, and further away and it would be too cold like Mars. This perfect positioning places Earth in what scientists call the "habitable zone" or "Goldilocks zone."

Liquid Water

Water covers over 70% of the Earth's surface. Without liquid water on Earth, life simply would not exist. It's important to note liquid water specifically, 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 that can support biological processes.

Atmosphere and Magnetic Field

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.

Earth's magnetic field protecting from solar radiation

Earth's magnetic field keeps the Sun's harmful rays at bay, creating a protective shield around our planet

Earth's 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 breathe. Obviously, without air there would be no life on Earth.

The Perfect Balance

All of these factors - distance from the Sun, liquid water, atmosphere composition, and magnetic protection - work together in perfect harmony to create the only known planet that supports life.

Frequently Asked Questions

How old is Earth?
Earth formed approximately 4.5 billion years ago from the gravitational collapse of a region within a large molecular cloud. The oldest known rocks on Earth are about 4 billion years old, and the oldest minerals (zircon crystals) date back to 4.4 billion years.
Why is Earth called the Blue Planet?
Earth is often called the Blue Planet because about 71% of its surface is covered by water. When viewed from space, the abundant oceans give our planet a distinctive blue appearance, especially since water reflects blue light from the Sun back into space.
What makes Earth unique in the solar system?
Earth is unique for several reasons: it's the only planet with liquid water on its surface, has a breathable oxygen-rich atmosphere (21% oxygen), maintains moderate temperatures suitable for life, has a strong magnetic field for protection, and most importantly, is the only known planet to harbor life.
How fast is Earth moving through space?
Earth orbits the Sun at an average speed of 67,027 mph (107,870 km/h), completing one orbit every 365.25 days. Additionally, Earth rotates on its axis at about 1,000 mph (1,600 km/h) at the equator, giving us our 24-hour day-night cycle.
What is Earth's magnetic field?
Earth's magnetic field is generated by the movement of molten iron in the planet's outer core. This magnetic field extends far into space, creating the magnetosphere, which protects life on Earth by deflecting most of the harmful solar wind and cosmic radiation that would otherwise strip away our atmosphere.
Last updated: 11 February 2026