Little is known how four billion years ago, life emerged on Earth out of a pre-biotic "soup" featuring complex organic molecules. Saturn's moon Titan is believed to resemble the pre-biotic Earth, because the large distance from the Sun has "deep frozen" its development state similar that of the early Earth. Tholins are a slush of complex organic molecules that instruments on the Huygens probe detected in Titans atmosphere. In a French laboratory experiments are now underway to recreate tholins in a Titan-like gas mixture...to ultimately understand how complex organic molecules--and which ones--might have been present in our own Earth's pre-biotic atmosphere.