Answer:
The goal of the famous 1953 Miller-Urey experiment was to test the Oparin-Haldane hypothesis, which postulated that Earth's early atmosphere was a reducing and could form organic compounds from simple molecules. They also suggested that the energy for this synthesis of organic compounds came from lighting and UV radiation.
As a result, Miller and Urey experiment created laboratory conditions like the ones thought to have existed on early Earth. Their apparatus included a warmed flask of water simulating the primeval sea and a system of hydrogen, methane, ammonia, and water vapor to mimic the hypothesized strongly reducing atmosphere on early Earth. They then discharged sparks, simulating lightning, in that atmosphere. The atmosphere was then cooled by a condenser, and water and dissolved compounds rained into the miniature sea. Interestingly, when Miller and Urey analyzed their collected samples, they discovered that this experiment yielded various amino acids found in organisms today such as alanine and glutamic acid as well oily hydrocarbons and other organic compounds. From these results, Miller and Urey concluded that the Oparin-Haldane hypothesis was correct: a strongly reducing atmosphere can produce organic molecules, a first step in the origin of life.