There are dozens of theories about the origin of the Earth. In general the theories of origin of the Solar System or earth can be divided into two groups: (i) Evolutionary theories (ii) Catastrophic Theories.
Evolutionary Theories: The theories which suggest that planets are formed during the evolution of the sun, are called ”Evolutionary Theories“. Nebular Hypothesis is an example of these theories.
Catastrophic Theories: ”Catastrophic Theories” are those which imagine that planets are formed by some special accident or catastrophe, such as the close approach of two stars or by collision of two stars. However, as the stars are so far apart in the galaxy, the possibility of such a catastrophe is extremely rare. the examples of Catastrophic Theories are the planetesimal and gaseous tidal hypothesis.