Courtesy of NASA (and DLR’s) Stratospheric Observatory for Infrared Astronomy (SOFIA), scientists have finally detected the universe’s oldest molecule, helium hydride, in space. Here’s everything you should know about this discovery:
Where was it found?
Helium hydride was detected in the planetary nebula NGC 7027, a cloud of dust and gas – the remnant of a sun-like star that perished ages ago.
Notably, NGC 7027 is located nearly 3,000 light-years away in the constellation Cygnus.
When were the first Helium Hydride molecules formed?
The early universe was way too hot for anything besides helium and hydrogen atoms to exist. Scientists believe it took about 100,000 years for the universe to cool enough for the first molecules to form.
It makes sense those first molecules would be helium hydride, and it would have been essential in the formation of the first stars as molecular hydrogen is generated when hydrogen reacts with helium hydride.
In a nutshell, helium hydride has been playing hide and seek with us for nearly 13 billion years
But.. Helium is a Noble gas that doesn’t usually combine with other elements?
Quite right. Being a noble gas, helium is fussy about combining with other elements. However, if the conditions have the right amount of UV radiation and heat, helium can combine with hydrogen.
Astronomers have long suspected that NGC 7027 would comprise of the ‘rare’ conditions required for this to happen.
More about SOFIA
The world’s largest airborne observatory, SOFIA is an 80/20 partnership of NASA and the German Aerospace Center (DLR). It’s basically an airplane—an extensively modified Boeing 747 SP aircraft carrying a 2.7-meter (106 inch) reflecting telescope.
This telescope recently received an upgraded device called the German Receiver at Terahertz Frequencies (GREAT), which added the necessary channel to scan for helium hydride. When astronomers pointed it at NGC 7027, the helium hydride signal was crystal clear.