Image of the entire sky in the x-ray spectrum, as seen from the Neutron star Interior Composition Explorer aboard the International Space Station.  The image is generated from 22 months of collected data.
The visible arcs form because NICER often follows the same paths as it moves between observation targets.
NASA/NICER
<a rel="nofollow" class="external text" href="https://svs.gsfc.nasa.gov/13214">NASA's Goddard Space Flight Center</a>