After decades of research, scientists have finally managed to detect in space the first type of molecule that formed in the universe, almost 14,000 million years ago: the helium hydride ion or hydrohelium (HeH +) . It is an important piece when it comes to understanding chemistry in the early cosmos and reconstructing what the process of its evolution was like.
Despite its importance in the history of the universe, hydrohelion had always escaped the observation of astronomers. However, now, an international team of researchers led by Rolf Güsten, from the Max Planck Institute for Radioastronomy, based in Bonn (Germany), has reported the unequivocal detection of the molecule in NGC 7027 – one of the smallest planetary nebulae. known, located in the constellation of the Swan (Cygnus), to about 3,000 years light of distance of the Earth.
They have achieved this thanks to the telescope of the Stratospheric Observatory for Infrared Astronomy (SOFIA), developed by NASA. Said airborne infrared telescope soars through the skies aboard a modified Boeing 747SP and flies into the stratosphere.
When after the Big Bang the temperatures in the primitive universe lowered, the new conditions allowed the recombination of hydrogen and helium, light elements that had been generated within minutes of the big explosion. At that time, the ionized hydrogen and neutral helium atoms reacted to form HeH + .
On the hunt for the elusive molecule
HeH + was unknown on Earth until 1925, the year in which they managed to synthesize it in a laboratory. However, searches carried out in space had not been successful so far, making it difficult to understand the underlying chemical networks, according to the Max Planck Institute for Radio Astronomy in a press release.
Rolf Güsten, lead author of the research and whose findings have been published in the scientific journal Nature , explains that “the chemistry of the universe began with HeH +” and further highlights that “the lack of definitive evidence of its existence in interstellar space has It was a dilemma for astronomy for a long time ”.
For his part, David Neufeld, from Johns Hopkins University, Baltimore (USA), and co-author of the article, highlights that the discovery of HeH + “is a spectacular and very beautiful demonstration of nature’s tendency to form molecules ”. “Despite the unpromising ingredients available, a mixture of hydrogen with the non-reactive noble gas, helium, and a hostile environment at thousands of degrees Celsius, forms a fragile molecule. This phenomenon can not only be observed by astronomers, but it can also be understood using theoretical models that we have developed ”, recalls the American researcher.
Image: NASA
