The origins of life on Earth have mystified and fascinated scientists for centuries. Now, researchers believe they have added a vital piece to the jigsaw with the discovery that, under certain circumstances, collisions between icy comets and planets produce amino acids, the basic building blocks of life.
The team from Imperial College London, the University of Kent and Lawrence Livermore National Laboratory simulated a 15,000mph collision and found that the amino acids were created in the searing heat and pressure of the impact, from a mixture of more basic substances found on comets, including ammonia, carbon dioxide and methanol, a form of alcohol.
The discovery also has implications for the hunt for extraterrestrial life. Ice on the surfaces of Enceladus and Europa, the moons orbiting Saturn and Jupiter respectively, could provide the perfect conditions for producing amino acids from meteor impacts.
In a paper published online by Nature Geoscience on Sunday, the researchers said their findings “suggest a pathway for the synthetic production of the components of proteins within our solar system, and thus a potential pathway towards life through icy impacts”.
Dr Zita Martins of Imperial College London said they had tried a range of different mixtures during the near four-year project before getting positive results.
“I’m not going to say it was a eureka moment, but I was extremely happy,” she said.
Earth was bombarded by comets and meteorites between 4.5 billion and 3.8 billion years ago and life is thought to have originated about 3.5 billion years ago.
Dr Martins said the next steps in the origin of life remained “one of the big questions” in science.