José Manuel NievesSEGUIRMadrid Updated: Save Send news by mail electrónicoTu name *
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According to a team of astronomers from the Steward Observatory of the University of Arizona, the complex organic molecules, these are known as the “building blocks of life” , are much more abundant in the Universe than previously thought. In fact, they are found in the greater part of the clouds of dust and gas that, by compressing due to its own gravity, giving rise first to the stars, and then planets.
Another conclusion of the study, to be published soon in The Astrophysical Journal and can be consulted on the server arXiv.org is that these precursor molecules of life appear in a stage much earlier than expected. In fact, there are already hundreds of thousands of years before our own star begin to form. The finding opposes head-on the current theories, according to which you will need an environment heated by the protoestrellas (stars in formation), so that organic molecules may exist.
For the first time, the authors of this research have sought out the signatures of two complex organic molecules, methanol and acetaldehyde , in a substantial number of possible places of birth of new stars. Previous observations had always been focused on the study of individual objects.
The so-called “cores pre-stellar” are so named because, although not yet contain stars, they mark regions in the space in which the dust and gases cool are coming together to give rise to the seeds of new soles.
In comparison with other objects in the universe, such as galaxies, the nuclei of pre-stellar form on time scales quite short, with a useful life of less than a million years. Driven by processes such as turbulence and gravitational forces, the gas and dust in the molecular cloud collapse to form filaments, and it is within these filaments that form the cores of stars more dense.
For their work, the researchers used the telescope 12-meter Radio observatory of Arizona on Kitt Peak, near Tucson. With this instrument they were able to “take a look” through the haze of dust and gas of 31 cores pre-stellar scattered in a region of star formation known as molecular cloud of Taurus, about 440 light years from Earth. Each one of those cores pre-stellar can reach to be extended along a distance equivalent to 1,000 solar systems lined up next to each other.
“The cores without stars that we have observed, says Yancy Shirley, co-author of the article – they are still several hundreds of thousands of years to start forming a star or a planet. And that tells us that the chemistry organic, basic need for life is already present in the crude gas before they begin to form stars and planets”.
scientists have known for some time that in the space there are molecules prebiotics, which provide the basic components necessary for life as we know it, but until now it has proved difficult to find out where and how these molecules are formed, as well as the mechanisms that continue to end up being on the surface of the planets.
First evolutionary steps
Samantha Scibelli, lead author of the research, “is still debating what exact type of processes are in play, because the theoretical models do not match with what we see. In this study, however, we tell the theorists as abundant of these molecules, and thanks to that, we can constrain better the mechanisms of formation that could be taking place”.
The cores, pre-stellar, in fact, are like open windows to the first evolutionary steps of stellar systems with planets and even life forms. Prior to this research, little had been studied about 10 objects of this type. And generally focusing on a single molecule, methanol.
The team of Sibelli, however, also sought, together with the methanol, acetaldehyde, a byproduct of alcohol that, among other things, is responsible for hangovers. And what they did during a campaign of observation of nearly 500 hours, during which we studied the 31 cores pre-stellar.
The results were surprising. The methanol was present in all the nuclei studied, and up to 70% of them also contained acetaldehyde. The study authors considered that these data are evidence that the complex organic molecules are much more widespread in regions of star formation than was thought until now.
Challenge front
These findings constitute a challenge in front of the traditional theories about how molecules are formed prebiotics, because they present a scenario in which the heat of the rising star, which was supposed necessary to the birth of the molecules, does not yet exist at all. That is why, the extraordinary abundance of complex organic molecules in clouds of gas and dust extremely cold means that, by force, must be running other processes, as yet unknown, for their formation.
“On the inside of these cores pre-stellar -explains Scibelli- , which we consider as child-care facilities or places of birth of low-mass stars similar to our Sun, the conditions are such that it is difficult to create those molecules. Thanks to studies like this we can better understand how the precursors of life exist, how they migrate and how they come to enter the solar systems after the stage of formation of stars”.
For Scibelli, the study of objects like the cloud of star-forming Taurus offer important clues to our own history. “Our solar system -explains the researcher – was born in a cloud like this, but that cloud is no longer there for us to see. Look at objects in space is like looking at a photo album with snapshots taken of different people at different stages of life, from her days as a baby to old age”.
