The seeds of life on Earth may have been flown in from space

While humanity continues our search for possible life on other planets, it’s important to note that we’re still figuring out the origins of life here on Earth. We know that the complex organisms of today evolved from much more basic, single-celled organisms, but even those cells had to be built from other, non-living ingredients. Getting the necessary components assembled would take a lot of luck, or perhaps a few Earth-bound comets.

Studies of comets, including celebrity-comet 67P by the Rosetta spacecraft, have found that they can be carriers of frozen water and amino acids. The 16 organic compounds found so far include polyoxymethylene, which is considered a possible template for carbohydrates and sugars commonly found on Earth. None of these components was considered to be samples of organisms, but the building-blocks were found in sufficient concentrations to suggest that comets are carrying some high-value materials.

Peptides created in comets’ crashes

Space-faring amino acids would have needed to be delivered to Earth of course, and recent simulations show that that delivery process may have also transformed them into more complex organic molecules. The energy from a comet impacting the Earth could have been the necessary catalyst to turn these froze ingredients into functioning peptides, which are chains of amino acids needed to make actual proteins.

While all this fills in more gaps in the timeline for the origins of life on this planet, it opens up some bigger questions at the same time. If the amino acids riding around on comets were able to kick-start life here on earth, what put them on the comet in the first place? And maybe more exciting, have they managed to “seed” any other locations with similar success?

Source: Comet impacts cook up 'soup of life' by Simon Redfern, BBC News