Universe's first molecule that formed almost 14 billion years ago, recently detected by NASA is __________.

Helium hydride ion (HeH+), the first molecule that formed almost 14 billion years ago, was detected by NASA's flying observatory SOFIA towards a planetary nebula. It is the first type of molecule (first molecular bond) that formed in the universe after the Big Bang. At that time, ionised hydrogen and neutral helium atoms reacted to form HeH+. Once the universe cooled down, hydrogen atoms started to interact with helium hydride, creating molecular hydrogen, which set the stage for star formation. From that point on, stars created the other elements of the cosmos.