Research from Australian scientists has revealed that during the formation of Milky Way-sized galaxies in space - around 9 billion years ago - they were filled with huge amounts of gas.
The researchers say this could explain why these galaxies were forming stars 30 times faster than they are today.
Studying distant galaxies allows scientists to essentially look back in time to see what was happening in the universe billions of years ago. Finding these gas reserves shows that galaxies the size of our Milky Way appear to have stockpiled most of their gas during the first few billion years of the Universe's history.
The researchers say their research shows that the physical processes which drive star formation in distant galaxies appear to be similar to those at play in the formation of local galaxies, including our own Milky Way.