The transformation of neutrinos in a neutron star merger could be crucial to shaping the way events of the collision unfold. Neutron star collisions certainly qualify as extreme, involving some of the densest objects in the Universe. Qiu and colleagues simulated neutrino transformations during neutron star collisions, tweaking various parameters, including the transformations involved. Neutron star collisions are known to be factories in which heavy elements are produced. For example, the researchers are unsure exactly how and when the transformations take place in neutron star mergers.