The planet Earth is a tiny part of a vast universe that has developed over a huge expanse of time.
Earth and its solar system are part of the Milky Way galaxy, which is one of many galaxies in the universe.
The sun is just one of a vast number (more than 200 billion) of stars in the Milky Way galaxy,.
The Milky Way is just one of a vast number (hundreds of billions) of galaxies in the universe.
The universe began with a period of extreme and rapid expansion known as the Big Bang.
This occured about 13.7 billion years ago.
Nearly all obsevable matter in the universe is hydrogen or helium, which formed in the first minutes after the Big Bang.
The history of the Universe, and of the structures and objects within it can be deciphered using observations of their present conditions together with knowledge of physics and chemistry.