NASA undated handout image shows an artist's conception of a storm of comets around a star near our own, called Eta Corvi. (Photo : Reuters)

Icy comets colliding with a planet can generate amino acids- the building blocks of life, according to a new study. Researchers found that amino acids can be produced even when rocky meteorites hit an icy planet. The findings may help explain the origins of life on earth.

The study team included researchers at Imperial College London, the University of Kent and Lawrence Livermore National Laboratory. To understand the effect of a comet hitting a planet, they recreated the impact by firing projectiles through a large high speed gun. The gun used compressed gas to shoot projectiles at speeds of 7.15 kilometers per second into targets. The targets were icy mixtures that had compounds similar to those found on comets.

Researchers found that the projectiles created amino acids such as glycine and D-and L-alanine. The study shows that amino acids can be produced when icy comets hit planets as the impact of the comet generates molecules. The heat from the impact transforms these molecules into amino acids.

"This process demonstrates a very simple mechanism whereby we can go from a mix of simple molecules, such as water and carbon-dioxide ice, to a more complicated molecule, such as an amino acid. This is the first step towards life. The next step is to work out how to go from an amino acid to even more complex molecules such as proteins," Dr Mark Price, co-author from the University of Kent, said in a news release.

Researchers said that we need to continue looking for traces of life on Saturn's moon Enceladus and Jupiter's moon Europa. These moons have conditions that can support life.

"Excitingly, our study widens the scope for where these important ingredients may be formed in the Solar System and adds another piece to the puzzle of how life on our planet took root," Dr Zita Martins, co-author of the paper from the Department of Earth Science and Engineering at Imperial College London, said in a news release.

The study is published in the journal Nature Geoscience.

Previous research supports the idea that life or compounds necessary for building life might have hitched a ride on comets or meteorites.