Some of these light - element nuclei also might be produced
by cosmic rays shattering atoms of carbon, nitrogen, oxygen, and other elements in the interstellar medium.
«The surface of Mars, the surface of Earth, and basically all surfaces in the solar system are being bombarded
by cosmic rays,» explains Farley, and when these
rays — very high - energy protons — blast into an atom, the atom's nucleus
shatters, creating isotopes of other elements.