- The universe’s first molecule, Helium hydride (HeH+), has been detected in space for the first time. Previously, helium hydride had been produced and tested in a laboratory setting.
- It has been spotted some 3000 light-years from Earth by an instrument aboard the airborne Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is a Boeing 747SP aircraft modified to carry a 2.7-meter reflecting telescope. It flies above the opaque parts of Earth’s atmosphere.
- The molecule was found in a planetary nebula, NGC 7027, which is the dusty remnant of a sun-like star.
- HeH+, a combination of helium and hydrogen, is thought to be created after the Big Bang. It was formed when decreasing temperatures in the young universe allowed recombination of the light elements produced in the Big Bang.
- The ions of the light elements viz. hydrogen, helium, deuterium and traces of lithium produced in Big Bang nucleosynthesis recombined in reverse order of their ionisation potential. Helium combined first with free electrons to form the first ever neutral atom.
- At that time, hydrogen was still ionised or present in form of bare protons. Helium atoms combined with these protons into the helium hydride ion HeH+.
- With the progress of recombination, HeH+ reacted with then neutral hydrogen and created the beginning of the formation of molecular hydrogen.
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