Comets could have seeded life on Earth To date, more than seventy varieties of amino acids have been found in meteorites and some in interstellar dust and gas clouds.It was observed that not only did a good fraction of the amino acids survive the collision, many had been polymerised into chains of two, three and four amino acids, so-called peptides, the first stage of building proteins.
What is more, freezing the target to mimic an icy comet actually increased the survival rate of the amino acids.
Is life a highly improbable event, or is it rather the inevitable consequence of a rich chemical soup available everywhere in the cosmos? Scientists have recently found new evidence that amino acids, the 'building-blocks' of life, can form not only in comets and asteroids, but also in the interstellar space. This result is consistent with (although of course does not prove) the theory that the main ingredients for life came from outer space, and therefore that chemical processes leading to life are likely to have occurred elsewhere. This reinforces the interest in an already 'hot' research field, astrochemistry. ESA's forthcoming missions Rosetta and Herschel will provide a wealth of new information for this topic.
See Is life the rule or the exception? The answer may be in the interstellar clouds for the rest of the article.