Comets really do hold key to how life began on Earth
LIFE on Earth could have been triggered by a comet strike billions of years ago, scientists said yesterday.
Key building blocks of life have been found on a comet 250million miles away, it emerged yesterday.
The discovery gives the first proof that comets carry the tools to create life – a theory scientists have long debated.
The breakthrough was made by the Rosetta spacecraft, which blasted off from Earth 12 years ago.
Rosetta has been orbiting the comet 67P/ Churyumov- Gerasimenko since August 2014, after a four-billion-mile hunt through space.
Now it seems the £1billion European Space Agency mission has achieved its main objective – finding out whether comets could hold the secrets to life itself.
According to results published last night in the journal Science Advances, the Rosetta craft has discovered clear evidence of the amino acid glycine, a basic component of proteins, and the mineral phosphorus, which helps to build DNA.
The team wrote: ‘Using instruments aboard Rosetta, scientists have detected glycine and phosphorus in the dusty envelope around the core of comet 67P/Churyumov- Gerasimenko, providing support for the idea that comets delivered key molecules for prebiotic chemistry throughout the solar system – and in particular to the early Earth.’
Scientists said comets may have ‘seeded’ planets with the raw ingredients of life.
The new evidence came from Rosina – the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis – an instrument designed to ‘sniff’ the gassy atmosphere around the comet. Scientists had already found simple organic molecules, but this is the first evidence that it also yields chemicals sufficient to build life.
Dr Matt Taylor, Rosetta’s British project scientist, said: ‘The multitude of organic molecules already identified by Rosina, now joined by the exciting confirmation of fundamental ingredients like glycine and phosphorous, confirms our idea that comets have the potential to deliver key molecules for prebiotic chemistry.
‘Demonstrating that comets are reservoirs of primitive material in the solar system, and vessels that could have transported these vital ingredients to Earth, is one of the key goals of the Rosetta mission. We are delighted with this result.’
Glycine is the smallest of 20 amino acids that link in chains to create proteins, the molecules that are fundamental to the structure and function of living cells.
In addition, phosphorus was found in the gaseous ‘coma’ around the comet.
Phosphorus is a mineral used in the body to make phosphate, which is vital to the structure of DNA as well as cell membranes, muscles, nerves and bones.
Rosetta had landed the Philae probe on the comet in November 2014 – a feat compared to a fly landing on a bullet.
Philae was meant to make the analysis of the comet’s gases that Rosetta has now made itself. But the probe landed in the shade of a cliff, meaning its solar panels could not power its instruments.