Experts say a death star galaxy is emitting a powerful jet of particles and radiation the could obliterate anything in its path.
MOREINFO: Astronomers believe the most likely victim of the death ray is another galaxy but they say the action is happening ten trillion kilometres from Earth so our own planet is almost certainly safe.
Scientists say a massive black hole is sending out a death ray deep in space that wipes out anything in its path.
They say the black hole was probably dormant and awakened by magnetic disturbances created by two galaxies in the process of a billion-year-long merger.
Such death rays have been observed before but experts say it's the first time they've caught one in the act of battering another galaxy.
SOUNDBITE: Doctor Daniel Evans, Harvard-Smithsonian Center for Astrophysics, saying (English):
"For the galaxy to be looking right down the line of sight, right down the barrel of the gun of that jet is extremely rare, so this makes it a really exciting discovery."
Such jets from black holes produce high amounts of radiation, particularly high energy x-rays and gamma rays.
Nothing resembling life on any planet could survive such a blast.
But the experts say Earth has nothing to fear.
The action is happening ten trillion kilometres out in space, 1.4 billion light years away.
Paul Chapman, Reuters