[reversecowgirl ] [reversedeepthroat ]
Black Holes of Known Mass #nasa #apod #ligo #nsf #blackhole #blackholes #blackholemerger #gw150914 #gw151226 #gw170104 #lvt151012 #ripples #spacetime #gravitywaves #interstellar #intergalactic #universe #milkyway #galaxy #space #science #astronomy
