What are the theories about how life was formed on earth?
There are currently many theories of life forming on Earth but I'll answer the most likely. The first is panspermia, the theory that comets delivered life to Earth. Secondly, lightning. Thirdly, deep sea.
The first theory, panspermia, is quite likely. Astronomers have found organic molecules on comets and asteroids, like the ones that may cause DNA to form. It is also thought that many asteroids today are preserving life in their cold icy hearts. When these asteroids bombarded Earth, they probably gave the rise to life too.
Secondly,lightning may have provided the spark needed for life to begin. Electric sparks can generate amino acids and sugars from an atmosphere loaded with water, methane, ammonia and hydrogen, as was shown in the famous Miller-Urey experiment reported in 1953, suggesting that lightning might have helped create the key building blocks of life on Earth in its early days.
Over millions of years, larger and more complex molecules could form. Although research since then has revealed the early atmosphere of Earth was actually hydrogen-poor, scientists have suggested that volcanic clouds in the early atmosphere might have held methane, ammonia and hydrogen and been filled with lightning as well.
Thirdly, life could've formed from the heat from geothermal vents in deep sea. the Earth was probably much cooler back then. The geothermal vents could have provided the heat needed for life to begin.
No matter how life was made, it should be admired, because it is beautiful.