The way dwarf galaxies move puts a new spin on galaxy formation

These satellites’ surprisingly organized orbits may challenge theories of dark matter

the giant galaxy Centaurus A

RIGHT ROUND  Dwarf galaxies near the giant galaxy Centaurus A, shown here in a composite of images from three different telescopes, seem to orbit it in an unexpectedly organized loop.

WFI (Optical)/ESO, A. Weiss et al. (Submillimetre)/APEX/ESO/MPIfR, R. Kraft et al. (X-ray)/CfA/CXC/NASA

Small galaxies are playing a game of ring around the rosie.