It is the lightest and most abundant element, after hydrogen, that can be found in the Universe.
Of every 1,000 atoms, approximately, randomly taken in the Universe, 839 are hydrogen, 159 helium and just 2 other heavier elements.
It is considered that most of the helium present in the Universe originated in the primordial phase, after the Big Bang, while only 15 percent would be the result of the nuclear reactions that take place in the heart of the stars.
In our Sun, for example, a fusion process is actively developed that leads to the transformation of hydrogen atoms into helium.
|◄ Previous||Next ►|
|Hale (observatories)||Heliocentric (theory)|