At least three times the amount of water found in Earth's oceans. An international team of scholars has observed it in the inner part of the disk of dust and gas revolving around the star HL Tauri, 450 light-years from our planet. The results of the investigation - published in Nature Astronomy - show the presence of a large amount of water vapor stably distributed in a precise region: a configuration that provides ideal conditions for the process of planet formation, just as it happened 4.5 billion years ago in our Solar System. "Until now, it has never been possible to map how water is distributed within a 'protoplanetary' disk, that is, in regions similar to where the planets of our Solar System presumably formed and where other planetary systems are forming," Leonardo Testi said in a note, professor at the "Augusto Righi" Department of Physics and Astronomy at the University of Bologna - With this study, we were able not only to detect the presence of a large amount of water in gaseous form, but also to capture detailed images that allowed us to measure the distribution of water vapor in a region of planetary formation 450 light-years away”. Water molecules are a key ingredient for the birth of planetary systems, of particular relevance is the so-called snow frontier, the distance from the star where water evaporates from ices. Indeed, theoretical models predict that stellar dust grains aggregate more rapidly in this area and the growth of embryos that will eventually form planets is favored. However, it is not at all easy to be able to observe from Earth the presence of water in the planet-forming regions because of absorption due to the large amount of water vapor in Earth's atmosphere. To overcome this obstacle, the scholars have relied on the extraordinary capabilities of ALMA (Atacama Large Millimeter/Submillimeter Array), a radio interferometer partnered by ESO (European Southern Observatory) that is located at an altitude of 5,000 meters in the Atacama Desert, Chile: the very dry environment and high altitude provide exceptional observing conditions that allow them to minimize the negative effects of the presence of water vapor in the atmosphere.
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