Actually it's not.
As best as we can tell the center (a ball of nickel/iron slightly smaller than the moon) is solid. The layer outside it is liquid.
The liquid part is liquid because it's hot (part gravity, part radioactive decay)
The solid part is also hot, but the pressure is great enough to solidify it.
Earth's mantle is a solid, not a a liquid, however it can deform in a ductile manner due to the very high confining pressures and temperatures. We know that Earth's mantle is solid because seismic S-waves can travel though it. S-waves are transverse or shear waves which cannot travel through liquids.
The debris from the birth of the sun formed rings and the materiel of the third ring (what would soon become the Earth) had the potential of H2O. It is liquid because of the right pressure and heat.
the outer core
Earth
On the earth there is air. There is no air on the moonAir, liquid water (There actually is frozen water on the Moon), life, Almost everything.On Earth, you can find liquid water, a substantial atmosphere, and lifeforms.
Earth
A moon called Titan, orbiting Saturn, has liquid methane, but on Earth its a gas. Also, under a moons surface, orditing Jupiter and know as Europa, there is scientific evidence that there is a sea, which has a posability of sustaining life, so we aren't the only ones in the solar system.
So far, Earth is the only planet we know of that has all three states of water.The three states of water are: liquid, solid (ice) and gas (water vapor).
Earth is the only known planet with liquid water.
earth
Earth.
no
Earth is the main planet with liquid water. There are some studies which say that Neptune and Uranus also contain water, deep inside them. However, only the Earth has liquid surface water.
clean water
Liquid Water
Earth
Water.
Water
Earth..?
The ocean