A fraction of a second after the Big Bang, all the primordial soup of matter in the Universe was 'broken' into its most fundamental constituents. It was thought to have disappeared forever. However scientists strongly suspect that the exotic soup of dissolved matter can still be found in today's Universe, in the core of certain very dense objects called neutron stars.
With ESA's space telescope XMM-Newton, they are now closer to test this idea. For the first time, XMM-Newton has been able to measure the influence of the gravitational field of a neutron star on the light it emits. This measurement provides much better insight into these objects.
Neutron stars are among the densest objects in the Universe.
