It has long been believed that the formation of the universe about 13.8 billion years ago during the Big Bang was followed about 100,000 years later by the creation of the first-ever type of molecule. As explained by Engadget, this molecule is known as helium hydride (HeH+), and scientists believe it was instrumental in helping the universe cool down ahead of the formation of the first stars. However, researchers had spent over nine decades trying to find evidence of HeH+ in space after it was originally discovered in a laboratory.
As detailed on Wednesday in a study published in the journal Nature, a team of scientists has finally discovered proof that helium hydride can indeed be found in space. According to CNN, the molecule was first produced in a lab in 1925, which then led to a “decades-long” search for its existence in space and several promising signs along the way. These signs were identified in the late 1970s by researchers who theorized that HeH+ could potentially be found in planetary nebulas — clouds of dust and gas formed by sun-like stars before they die out in explosive supernovas.
“The chemistry of the universe began with HeH+,” read a statement from study author Rolf Gusten, an astronomer at the Max Planck Institute for Radioastronomy. “The lack of definitive evidence of its very existence in interstellar space has been a dilemma for astronomy for a long time.”
As the opaque nature of Earth’s atmosphere makes it impossible to detect helium hydride’s signal with ground-based telescopes, Gusten and his colleagues made use of the Stratospheric Observatory for Infrared Astronomy (SOFIA) — a “modified” Boeing jet, as CNN described it — to find evidence of the molecule. Using the German Receiver at Terahertz Frequencies (GREAT) instrument aboard SOFIA, HeH+ was detected in NGC 7027, a planetary nebula some 3,000 light-years away from Earth, thus backing up the aforementioned predictions.
JUST FOUND: The 1st type of molecule ever formed in the universe. ⚛️
Scientists using our @SOFIAtelescope have located helium hydride in our own galaxy. It is a contributor to the formation of the 1st stars. Unveil our cosmic beginnings: https://t.co/cpaSeV8F8s pic.twitter.com/MNnV4VOZwH
— NASA (@NASA) April 17, 2019
In a separate statement, study co-author David Neufeld, a professor at Johns Hopkins University’s Physics and Astronomy Department, said that the helium hydride discovery marked a “dramatic and beautiful” example of how molecules can naturally form.
“Despite the unpromising ingredients that are available, a mixture of hydrogen with the unreactive noble gas helium, and a harsh environment at thousands of degrees Celsius, a fragile molecule forms,” Neufeld added. “Remarkably, this phenomenon can not only be observed by astronomers but also understood using theoretical models that we have developed.”
Although the new findings have largely been heralded as an exciting development, one expert believes that more research might be needed to be absolutely sure that helium hydride can be found in space. As cited by The Guardian, University of Georgia professor Phillip Stancil, who was not involved in the study, explained that only one HeH+ signature was spotted, as opposed to the two that are typically required in order for scientists to truly confirm a molecule’s existence.
The above criticism was, however, countered by Gusten, who was quoted by The Guardian as saying that there is only a “negligible” chance that his team’s discovery was a false positive.
“The lack of evidence of the very existence of helium hydride in the local universe has called into question our understanding of the chemistry in the early universe,” Gusten explained. “The detection reported here resolves such doubts.”