Artist's impression shows an oblique view of our Milky Way galaxy. The black-hole system GRO J1655-40 is streaking through space at a rate of 400 000 kilometres per hour - 4 times faster than the average velocity of the stars in the galactic neighbourhood. The yellow star is our Sun.

Credit: European Space Agency, NASA and Felix Mirabel (the French Atomic Energy Commission & the Institute for Astronomy and Space Physics/Conicet of Argentina)