Artist's conception shows two merging black holes similar to those detected by LIGO. The black holes are spinning in a non-aligned fashion, which means they have different orientations relative to the overall orbital motion of the pair.

Courtesy of LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)

Artist's conception shows two merging black holes similar to those detected by LIGO. The black holes are spinning in a non-aligned fashion, which means they have different orientations relative to the overall orbital motion of the pair. Courtesy of LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)