The correct answer is - 4.543 billion years.
Our planet, the Earth, is considered to have formed approximately 4.543 billion year ago. It is thought that the Earth had formed at roughly the same time with the other planets, or rather they all formed in a relatively small space of time.
The Earth is part of the inner planets, and it is the the third most closest to the star in our galaxy, the Sun. Also, it is the only planet on which is known that life can exist, at least so far, as it is the only planet that provides the right conditions for the development of living organisms.
The biggest interaction that the Earth has is with the gravitational pull of the Sun and the Moon, the only natural satellite of the Earth.
