Astronomers are used to finding organic molecules in outer space: it has been possible to verify the presence of more than 70 molecules in the interstellar medium, where the heaviest are made up of chains of 11 atoms. For example, in the center of the Galaxy there is enough alcohol to fill several trillion bottles of whiskey . On the other hand, organic molecules have also been found in meteorites. In fact, the first in which amino acids were discovered was in the Murchinson, which fell in Australia in 1972. After careful analysis the scientists found 74 amino acids. Eight of them appear in the proteins of terrestrial organisms and 11 play some other role in the biology of our planet, but the remaining 55 were unequivocally extraterrestrial. This discovery, later confirmed after analyzing other meteorites such as Murray, shows that amino acids can be formed in hostile environments such as the cold of space , and that this occurred during the infancy of our Solar System. But the most fascinating thing is that the bases that make up our DNA have also been found in them.
So it is not too strange to think that a protein could one day be found, which is nothing more (or less) than a gracefully linked chain of amino acids. This is what the team led by Malcolm McGeoch of Plex Chemical Corporation (a Massachusetts chemical company, USA) claims to have found in the Acfer 086 meteorite that fell in Algeria in 1990. The new protein, christened by the researchers as’ hemolithin ‘, is a chain of the amino acids glycine and hydroxyglycine that is not found on our planet. Also, the proportion of deuterium it contains (the isotope of hydrogen that has a neutron and a proton in its nucleus instead of just a proton) is similar to that found in the Oort cloud .
However, the scientific community remains skeptical about this . There are many gaps and questions to answer to be able to affirm without ambiguity that it has an extraterrestrial origin, although nobody denies the possibility that one day non-terrestrial proteins will be discovered.
Is hemolithin an alien protein?
The truth is that this news has rekindled interest in panspermia, the hypothesis that places the origin of life outside our planet. It was first enunciated by the Swedish chemist Svante Arrhenius in 1903, when he suggested that microscopic forms of life, such as spores, could be found in space and occasionally fall on a planet, seeding it with life.
Could life come from outer space? Saving the outlandish proposal by astrophysicist Fred Hoyle in the 1970s that some viruses might reach Earth riding comets, some scientists argue that perhaps a significant amount of the basic building blocks of life arrived on board those dirty snowballs or like wandering rock travelers . Among the experiments that support this idea are those carried out in the 90s at the LDEF ( Long Duration Exposure Facility ) mission: Bacillus subtilis spores were exposed to space for 6 years and more than 70% survived, which means that, suitably protected – such as the outer layers of the rocks in which they are found – life can resist in space. This result was confirmed by another series of experiments carried out by Gerda Horneck’s team, from the German Aerospace Center, in 1994, 1997 and 1999.
In 2000, an article appeared in the Proceedings of the National Academy of Sciences about tiny molecular capsules that enclose gases from when the Solar System was formed. As asteroids and comets were formed, these capsules, built with carbon atoms, were trapped inside them and remained that way until, billions of years later, one fell on our planet and scattered its contents. Miraculously, some of them did not break. This discovery supports the hypothesis that the gases that make up Earth’s atmosphere could have come from space during the Bombardment Age, about 4 billion years ago. Then our young and incandescent planet was subjected to an intense cannonade, where asteroids contributed gases and comets, water – some think that 30% of the water we drink comes from then-. So it is not unreasonable to think that they could also contribute the organic compounds with which life was built.
Isn’t it ironic to think that we are aliens on our own planet?
