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YOUR BLUE HOME
The third planet from the Sun is your home. The Earth is the only known planet where life can survive. As far as we know, there is no other planet in the universe like Earth. We have a very narrow temperature range that allows water to remain a liquid. Life has developed over millions of years because of that liquid. What else makes us special? Most of our atmosphere is made of nitrogen (N), a relatively inert gas. If we had clouds of sulfuric acid or methane (like other planets), life may have never developed.
A SURFACE THAT FLOATS
There are also huge landmasses on our planet. The rock plates that float across the surface are called tectonic plates. Those plates float on the liquid region called the mantle. The mantle is an area between the core and the crust that is filled with molten rock. It is kept in a liquid state because of the energy given off by the center (core) of the Earth. Scientists have also discovered that pressure increases as you move towards the center of the planet. The core of the Earth has extreme temperatures and pressures that keep the iron (Fe) and other metals liquid and flowing.
MAGNETIC FIELD ARMOR
Flowing metal in our planet helps create something called a dynamo effect. Dynamos create large magnetic fields. In the case of the Earth, the magnetic field protects our planet from space. This protective cover is called the magnetosphere. It shields us from the solar winds and solar radiation. You can see where solar winds and the magnetosphere collide when you see the Aurora Borealis (northern hemisphere) and the Aurora Australis (southern hemisphere).
BUILT FOR LIFE
Although many planets in the Solar System have atmospheres, ours protects us from space and encourages life. With an atmosphere made up of 78% nitrogen (N), 21% oxygen (O), and 0.03% carbon dioxide (CO2), life has thrived on this planet. Our atmosphere has many layers divided by different temperatures and pressures. The atmosphere also provides the planet with protection. The ozone (O3) that surrounds Earth filters out ultra-violet light. The density (thickness) of the atmosphere helps to vaporize many solid particles colliding with the planet. As you can tell, the atmosphere serves many purposes.
Multimedia Features
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Glowing Aura
NASA's Aura spacecraft is offering new insight into the Earth's atmosphere. (NASA/KSC)
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- Aura Home Page
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Drifting Pollution
By monitoring pollutants, NASA seeks to develop scientific understanding of how Earth copes with natural and man-made hazards. (NASA/KSC)
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