What makes Earth our home planet?
Land, water, air and life are connected. A globe helps us understand.
The short answer
Earth has liquid water, a protective atmosphere and conditions suitable for life as we know it. These conditions work together. So far Earth is the only planet where life has been confirmed.
Puschel and Flauschi in the museum. Earth model with oceans, an air layer and a landscape with living things. Simplified inanimate museum model; arrows and colours help explain it. AI-created illustration, not a photograph of nature.
Explained in three pictures
1 Liquid water
Liquid water matters for the life we know.
2 Air and warmth
Air contains oxygen and affects warmth.
3 Confirmed life
Life has been confirmed on Earth.
More about the picture
Our home planet provides liquid water, an atmosphere and conditions in which the life we know can thrive. So far, life has been confirmed only on Earth. That does not prove that no life exists elsewhere.
An imagined Wusel scene
Puschel and Flauschi investigate
At the planet model, Puschel wants to mark only water as a condition for life. Flauschi adds cards for air and temperature. They consider what would be missing if one card were removed. He links them: the conditions must work together.
Look closely
Compare the museum model with the three picture steps. Air contains oxygen and affects warmth.
An example to help you understand
Draw a hundred equal boxes and colour 71 blue. This models ocean surface coverage, not water inside Earth. Find a coastline on a globe. With a torch as the Sun, slowly rotate the globe while keeping the torch still. Your point moves from light to darkness. This models day and night, not all weather processes.
Try explaining it
Which conditions work together for our life on Earth?
Choose a), b) or c), then explain your choice.
- a)Liquid water, suitable temperatures and a protective atmosphere.
- b)A suitable temperature alone, even without water and air.
- c)An atmosphere alone, regardless of water and temperature.
Show the explanation
Correct: a): Liquid water, suitable temperatures and a protective atmosphere.
Earth has liquid water, a protective atmosphere and conditions suitable for life as we know it. These conditions work together. So far Earth is the only planet where life has been confirmed.
Word help
- oxygen
- A gas in air that our bodies take in through breathing and need for their work.
- atmosphere
- The gas layer around a world; on Earth it is the air above us.
- orbit
- The path of one body around another.
- rotation
- Turning around one's own axis.
- axis
- An imaginary line around which something turns; in machines it may also be a physical part.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
1. A rocky planet
Earth is the third planet from the Sun and one of the four inner rocky planets. It has a rocky structure and solid surface, including mountains, valleys, continents and ocean floors. We stand on its thin outer layer. Earth is not a flat disc; a globe reduces its approximately spherical shape to a model. That outer layer is the crust. Beneath it lies the much thicker rocky mantle, then the mainly metallic core. The outer core is liquid and the inner core solid. A rocky surface does not mean every part inside Earth has the same physical state.
2. Water covers much of the surface
Oceans cover about 71 percent of Earth’s surface. Percent means “out of a hundred”: about 71 of a hundred equal-sized surface patches would be ocean. This does not mean 71 percent of the whole planet is water. Oceans are thin layers compared with Earth’s diameter. Liquid water matters for life as we know it.
3. Air is more than oxygen
The atmosphere is Earth’s gas envelope. Near the surface it contains about 78 percent nitrogen,21 percent oxygen and a small remainder of other gases. We need oxygen to breathe, but air is not pure oxygen. The atmosphere influences weather and warmth and blocks some harmful radiation. It is not a rigid transparent glass cover.
4. Day, year and life
Earth rotates while orbiting the Sun. A day is about 24 hours, an orbit about 365¼ days. Rotation produces day and night; the tilted axis matters for seasons. The axis is an imaginary line from the North Pole to the South Pole, around which Earth turns. Earth is currently the only planet with confirmed life. That does not prove there is none elsewhere: researchers continue searching for evidence.
An optional question for further exploration
You can use the longer explanation above. This is extra, not needed for the first quiz.
An extra question
Does 71 percent ocean coverage mean 71 percent of Earth’s interior is water?
Discover the answer
No. The number describes the surface. Most of the planet consists of rock and metal, with oceans forming a relatively thin layer outside.
Pictures and sources for adults
Sources for further reading
Facts checked against the specialist sources below on 12 October 2026. The Wusel scene is fictional; comparisons and simplified models are explicitly explained. Sources are in English.