Origin of organic molecules There are two possible sources of organic molecules on the early Earth : Terrestrial origins - organic synthesis driven by impact shocks or by other energy sources -LRB- such as ultraviolet light or electrical discharges -RRB- -LRB- eg .

Origin of organic molecules There are three sources of organic molecules on the early Earth : organic synthesis by other energy sources -LRB- such as ultraviolet light or electrical discharges -RRB- -LRB- eg .
