An illustration of a neutron star collision creating platinum, gold, and other precious heavy elements.
Neutron stars that crash together in space forge valuable metals like silver, gold, and platinum.
Europium, one of the least-common elements in the universe, is a candidate and is used in TVs, lasers, and plastics.
A neutron-star collision discovered through gravitational waves made about 1-5 Earths' worth of the europium, according to a new study.
This material almost immediately decayed into lighter elements, leading to a bright, radioactive "kilonova" astronomers could see some 85 million to 160 million light-years away from Earth.
Researchers who've pored over the data since last year now think the collision also made 1-5 Earth masses of a very rare element called europium, according to a recent study in The Astrophysical Journal.