A distant galaxy has been spotted feeding off a gigantic cloud of gas.
The simplest models of galaxy formation involve clouds of gas and material collecting together and combusting, forming stars and eventually planets like our own.
But those theories do not allow for the continued growth of galaxies, which should otherwise have used up their fuel.
Above: artist's impression of the galactic feast
The European Southern Observatory's Very Large Telescope spotted a galactic feast taking place, in which one galaxy 'feeds' on a cloud of gas in deep space.
The find gives the best evidence yet of the process by which very large galaxies continue to grow after their formation.
The galactic meal was spotted thanks to the presence of a nearby quasar - HE 2243-6 - a massive back hole at the centre of another, even more distant galaxy.
Above: the space around quasar HE 2243-6
In a press release the ESO epxlained how the technique works:
"The light from the quasar passes through the material around the foreground galaxy before reaching Earth, making it possible to explore in detail the properties of the gas around the galaxy."
It represents the best evidence so far that galaxies devour nearby gas to grow and form stars.
The light from the distant object originates from just two billion years after the big bang.
"The properties of this vast volume of surrounding gas were exactly what we would expect to find if the cold gas was being pulled in by the galaxy," said Michael Murphy (Swinburne University of Technology, Melbourne, Australia), co author of the study that appears in the journal Science.
"The gas is moving as expected, there is about the expected amount and it also has the right composition to fit the models perfectly. It's like feeding time for lions at the zoo -- this particular galaxy has a voracious appetite, and we've discovered how it feeds itself to grow so quickly."