An important constituent of living beings which includes ingredients of DNA like protein glycine and phosphorous has been detected in the Comet 67P/Churyumov-Gerasimenko.
This give credence to the theory water and organic molecules were brought to Earth by asteroids and comets which periodically impacted the planet.
Discovery of Components of DNA
Glycine which is a protein found in DNA, the basic element of life ‘s hard to discover and is very inert. It sublimates at a temperature slightly below 150 degrees centigrade and hence microscopic amount is released as a gas in the very cold surface of the comet.
Experts opine that there is a strong association linking dust and the protein, and it is probably released from the dust in the icy covering of comet once they warmed up.
Researchers have also detected other organic molecules such as methylamine and ethylamine, which are the predecessor to forming glycine.
It is one of the only amino acids which can be formed without the involvement of water. Hence, the occurrence of methylamine and ethylamine and the relation between dust and amino acid gives a clue to its formation.
The incidence of the Amino acid has repeatedly been confirmed by Rosetta spacecraft in the fuzzy 67P/C-G atmosphere.
The spacecraft first detected the essential building blocks of life in October 2014, and measurements in greater details were taken in August 2015 when the comet approached the closest point to the Sun and outgassing was strongest.
Phosphorus, a key element for physical living forms
Another discovery was the detection of Phosphorous, which is also an essential ingredient in the cell wall and also in both DNA and RNA.
The findings confirm that comets and asteroids are depots of primitive materials in the Solar System and could have acted like seeds for kick starting life on planets like Earth where the conditions are conducive to life.