Helium hydride ions, thought to be the first type of molecule to form in the universe, have finally been spotted in space.
These charged molecules, each made of a neutral helium atom and a positively charged hydrogen atom, first emerged within about 100,000 years after the Big Bang. Back then, the universe was composed almost entirely of hydrogen and helium, and helium hydride was the only molecule that these two elements could create when they collided.