~100,000 years after the Big BangReputable sourceWell documented
Helium Hydride: The First Molecule
On the timeline · around ~100,000 years after the Big Bang · The First Instants
What happened
As the young universe cooled, helium and hydrogen joined to form helium hydride (HeH⁺) — the very first molecule. NASA's SOFIA observatory finally detected it in space in 2019, decades after scientists predicted it should exist.
Why it matters
It marked the dawn of chemistry in the cosmos — the first step on the long road from bare atoms to molecules, stars, planets and life.
Sources
- NASA. First Molecule Found · Reputable source