Comets really could have sparked life on Earth, scientists have proven for the first time, after finding key components of cells present on the atmosphere of space rocks.

Exerts have long believed that comets and asteroids brought water and amino acids when they crashed into the planet during the ‘bombardment phase’ around four billion years ago.

But the building blocks of life have proved elusive, leaving scientists wondering if they could have survived the extreme conditions of space.

Now, the team behind the Rosetta comet landing mission have announced they have found the amino acid glycine and the element phosphorous in the dust surrounding 67P/Churyumov-Gerasimenko.

Both glycine and phosphorus are crucial to the structure of DNA, proteins and cell membranes. Crucially the finding suggests that if comets transported the ingredients of life to Earth, they may have transported them elsewhere, raising the prospect of life on other planets.

Rosetta project scientist Dr Matt Taylor said: “This result is one of the main things we were looking for with Rosetta.

“This means that comets contain an awesome cocktail of organics material that, if provided with the right conditions, could then go on to form life.

“So, in the case for Earth, this support the idea that comets impacting Earth could provide the right ingredients for life.