According to Japanese researchers, the impacts helped to form amino acids, reinforcing the hypothesis of the extraterrestrial origin of the building blocks of life.
A study by astronomers at Tohoku University in Japan revealed that asteroid impacts during Earth’s formation were crucial to the appearance of the molecules that, over time, gave rise to life as we know it.
Two hypotheses try to explain the origin of the building blocks of life on our planet: one claims that it is extraterrestrial – that the molecules were brought by rocks from space; and the other is endogenous formation – which states that the molecules formed on their own on our planet. According to the researchers, the new study indicates the first hypothesis as the most likely.
To reach this conclusion, scientists simulated the reactions resulting from the impact of a meteorite in the ocean. To do this, they investigated the interaction between carbon dioxide, nitrogen, water, and iron in a laboratory using a single stage propellant gun.
According to the team, these substances were chosen because they were two of the main components of the atmosphere on Earth more than 4 billion years ago. “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 Yoshihiro Furukawa, co-author of the research, in a statement.
After running the simulations, the scientists were able to notice the formation of amino acids such as glycine and alanine, considered the building blocks of life. “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,” explained Furukawa.
Ancient life on Mars
The hypothesis that an ocean once existed on Mars also creates interesting ideas for further studies. This is because it is likely that carbon dioxide and nitrogen were the main gases that made up the Martian atmosphere when the Red Planet had an ocean, and therefore the formation of amino acids may also have happened. “Further investigations will reveal more about the role meteorites played in bringing more complex biomolecules to Earth and Mars,” noted Furukawa.