The first-ever detection of the universe’s oldest molecule in space marks a pivotal moment in scientific discovery. This primordial molecule, known as the helium hydride ion (HeH+), originated nearly 14 billion years ago during a period of declining temperatures that followed the Big Bang. Its composition — hydrogen, helium, deuterium, with traces of lithium — was indicative of the light elements prevailing at the time.
As the universe cooled, reactions between ionized hydrogen and neutral helium atoms began to occur, leading to the formation of HeH+. This creation marked the inception of molecular bonding, a process essential in the structure of the cosmos.
The Role of HeH+ in Star Formation
Helium hydride served a critical role in laying the groundwork for star formation. Post its formation, hydrogen atoms started interacting with helium hydride, birthing molecular hydrogen. This action set the path for star formation, which subsequently led to the creation of other cosmic elements.
Despite being a crucial part of early Universe history, HeH+ had evaded detection in astrophysical nebulae – clouds of gas and dust found in outer space.
Detection of Helium Hydride
NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) successfully detected helium hydride, marking a significant breakthrough. This combination of helium and hydrogen was found approximately 3,000 light-years away from Earth.
SOFIA is a modified Boeing 747SP jetliner equipped with a 100-inch diameter telescope. The joint venture between NASA and the German Aerospace Centre operates at roughly 45,000 feet, enabling observations to be free of interference from Earth’s atmosphere. SOFIA’s unique design allows it to return to Earth post every flight, giving scientists the opportunity to continuously upgrade its technology.
One such recent upgrade encompassed the addition of a specific channel designed to detect helium hydride signatures, a feature absent in previous telescopes.
| Helium Hydride | SOFIA |
|---|---|
| First type of molecular bond formed post Big Bang | A Boeing 747SP jetliner modified to carry a 100-inch diameter telescope. |
| Aided star formation | A joint project of NASA and the German Aerospace Centre |
| Detected approximately 3,000 light-years away from Earth | Operates at roughly 45,000 feet |
The Discovery of HeH+ in Space
The elusive molecule was finally found in a planetary nebula, NGC 7027, which is essentially the dusty remnants of a sun-like star. While helium hydride had been synthesized and tested in laboratory settings, this discovery signified the debut detection of the molecule in space, casting a new light on the chemistry of the early universe.
