Earth

Explanation

View of the Earth as seen by the Apollo 17 crew travelling toward the Moon.

Earth is the third planet from the Sun, which is where life as we know it thrives upon in this solar system. 4.5 billion years ago, Earth formed out of the gases and clouds of dust from the accretion disc of the solar nebula that created the solar system and the rest of the planets in it. Earth has a natural satellite, called as the Moon.

Frequently Asked Questions

Why does the Earth spin?

The Earth spins due to its inertia. Roughly, 4.5 billion years ago, when the hydrogen atoms in the solar nebula slowly collapsed down on its own gravity, a denser region formed at the centre of the cloud. As the distribution of the mass collapsed towards the centre, the spin of the entire cloud increased to conserve the angular momentum by nature. As it began to spin faster, it created the accretion disc where the protoplanets would form later. The hydrogen atoms and the particles in the disk inherited this spin too. Earth, being formed in the same way from the particles, it inherited its own average spin out of them. And by the law of inertia, Earth will continue to spin undisturbed until some unbalanced forces or any impacts would change its current state of motion.

How did the Earth form?

The Earth formed inside the accretion disc when the heavier particles started attracting smaller particles and began to clump together to eventually form a planet sized body.