Researchers from UC Santa Cruz and elsewhere are examining the observations, which show abundance of aluminum-26, an isotope of the element aluminum.
Isotopes are heavier forms of elements, containing more neutrons in an atomic nucleus than the ordinary atom. They are often unstable and prone to decaying into lighter elements, a radioactive process that releases heat. A nuclear power system generates heat from the decay of radioactive atoms in a similar way.
Though most of the aluminum-26 originally infused in our solar system’s primordial star-forming cloud has long since decayed, the elements it broke into remain, preserved in meteorites fallen to Earth.