Scientists at Tohoku University may be one step closer to unraveling the mystery of the origin of life on Earth. The researchers have discovered that ancient asteroid impact sites may provide important clues as to how the essential building blocks of life formed on the planet.
The experts found evidence that amino acids emerged at the sites of asteroid crash impacts in the ocean. These compounds make up proteins, which are one of the four main molecular components needed to support all forms of life.
The research highlights the role of meteorites in transporting life’s essential molecules to Earth, and potentially to Mars.
The origin of life on Earth is the one of the biggest scientific problems that is yet to be solved. Life can be traced back to non-living organic compounds, but there are many conflicting theories about how these building blocks first appeared and how they came together.
The presence of amino acids and other biomolecules in meteorites suggests that they provided a mode of extraterrestrial delivery.
For the current study, the experts simulated the reactions that occur between carbon dioxide, nitrogen, water, and iron when a meteorite crashes into the ocean. Carbon dioxide and nitrogen were used because these gases were present in the atmosphere on the Hadean Earth, which existed more than 4 billion years ago.
The simulation produced amino acids such as glycine and alanine. These amino acids are components of proteins that catalyze many biological reactions.
“Making organic molecules form reduced compounds like methane and ammonia are not difficult, but they are regarded as minor components in the atmosphere at that time,” said study co-author Yoshihiro Furukawa.
“The finding of amino acid formation from carbon dioxide and molecular nitrogen demonstrates the importance in making life’s building blocks from these ubiquitous compounds.”
The fact that an ocean may have once existed on Mars, and that carbon dioxide and nitrogen were likely the major constituent gases of the Martian atmosphere when the ocean existed, suggests that amino acids could have formed there as well.
“Further investigations will reveal more about the role meteorites played in bringing more complex biomolecules to Earth and Mars,” said Furukawa.
The study is published in the journal Scientific Reports.