The First Molecular Bond in the Universe has been Found

The First Molecular Bond in the Universe has been Found

The First Molecular Bond in the Universe has been Found
Image Credits: CNet

Scientists have finally detected the first molecular bond (Helium Hydride) to be ever created in the universe by observing NGC 7027, a planetary nebula.

The discovery of the Helium Hydride ion (HeH+), finally closes yet another chapter in the annals of space discoveries. Previous attempts to detect the Helium Hydride ion in space were restricted by the limited resolving power of existing spectrometers at the appropriate wavelengths. This time around, scientists have managed to find a way to overcome this constraint.

The Creation of H2

Helium and Hydrogen were the first two elements to come into existence after the birth of the universe. The energetic beginning of our universe resulted in a massive pool of ions that combined with the surrounding free electrons to form neutral atoms as soon as the temperature started to fall towards 4000 K. The neutral Helium atoms then hooked up with a proton to form Helium Hydride – the first molecular bond in the history of the universe. This bond was eventually destroyed by a process that led to the creation of molecular Hydrogen.

Is HeH+ a New Thing for us?

An interesting thing is that Helium Hydride was first observed on Earth (in laboratory conditions) in 1925. Ever since then, repeated attempts and research projects have been made to observe the first molecular bond. It was believed to exist in abundance in planetary nebulae, which is ejected in a field envelope at the last stage of a star. During this phase, the rising temperatures result in a large-scale ionization which seemingly leads to the formation of HeH+. David Neufeld, a Co-author of the study who is a Professor in the Physics and Astronomy Department at John Hopkins University, described the discovery perfectly by saying,

“The discovery of HeH+ is a dramatic and beautiful demonstration of Nature’s tendency to form molecules. 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 form. Remarkably, this phenomenon can not only be observed by astronomers but also understood using theoretical models that we have developed.”

Why NGC 7027?

Around 10,000 of these short-lived, glowing objects (planetary nebulae) are estimated to exist in our galaxy. Although only 1,500 have been actually discovered, the rest remain unseen behind interstellar dust. Having said that, the question that needs to be answered is why NGC 7027 was chosen out of all the known nebulae.

The process was initiated when the researchers from the Max Planck Institute for Radioastronomy, in Germany, reported about the existence of the rather elusive ion in a planetary nebula called NGC 7027. Stratospheric Observatory for Infrared Astronomy (SOFIA) was used to gather data using a high-resolution spectrometer. Over the course of three flights in 2016, the team trained SOFIA’s telescope on NGC 7027, which is about 3,000 light-years from Earth. It was believed to be the prime candidate to look for the ‘first-ever molecular bond’ because it is a very young nebula and has the potential to exhibit conditions that existed at the creation of the universe.

Significance of Discovering the First Molecular Bond

While some scientists claim that this discovery has limited importance, many researchers are of the stance that the chemistry of the universe began with this ion. The situation was beautifully summed up by an astronomer in the following words:

“The lack of definitive evidence for its very existence in interstellar space has been a dilemma for astronomy. The unambiguous detection reported here brings a decades-long search to a happy ending at last.”

This astrophysical observation of the first molecular bond marks a pivotal point of humanity’s understanding of the starting point of the universe. Similarly, it explains how the world’s first chemical reaction led to the complex interweb of chemical bond formations that hold together the world as we know it today. Finding the first ever molecular bond to exist and that too just after getting the first image of a black hole is simply mesmerizing. Astronomer Rolf Güsten mentioned that we can now put constraints on the chemical reactions that control the formation and destruction of the helium hydride molecule which will give a completely new dimension to our research. He said,

“The respective rates are difficult to calculate, and in the literature have changed by a factor of 10 in recent years. Our observations will help to ‘calibrate’ these rates, and this will feed-back into the chemical ‘networks’ of the early Universe.”

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