Journey through time: Planet Earth 5 billion years ago

It is thought that the Earth was made about 4.6 billion years ago when pieces of the giant disc-shaped cloud of matter that also made the Sun crashed into each other. Gravity slowly pulled this gas and dust together into clumps that became asteroids and small early planets called planetesimals. These things kept hitting each other and getting bigger, which is how the planets in the Solar System, including Earth, were made.

Still being worked out are the specifics of how the Earth came to be. Scientists look at meteorites and the oldest rocks on Earth to learn more about what happened in the Solar System when it was first forming. They also look at other suns in our galaxy, which is called the Milky Way. Let’s watch the video then:

Astronomy