NO body of you think about how earth form?
Earth form 4.6 billion year ago.When explossion occur in sun. Due to this some part of sun gone away.
This hot part of sun start cool down and form sub atomic particals(Proton .Newtron Electron).
These subatomic partical combines and form lighter elments (H ,He etc )..And these lighter element form planets.{Big Bang Theory }
Now age of earth is 4.6 billion year.