When astronomers peer deep into space, they are effectively looking back in time to a period much earlier in the universe's history. That is because light from these regions takes so long to reach us.
Now, an international team of researchers has made unprecedented observations of two small, newborn galaxies which appear as they existed 800 million years after the Big Bang.
For the first time, astronomers have been able to detect the internal 'whirlpool'-like motion of gases in galaxies at this early stage in the universe's history.
They made the findings using the Atacama Large Millimeter/submillimetre Array (Alma) in Chile. Their results have been published in the journal Nature.
"Until Alma, we've never been able to see the formation of galaxies in such detail and we've never been able to measure the movement of gas in galaxies so early in the universe's history," said co-author Stefano Carniani of the University of Cambridge.
Using infrared light data collected by Alma, the astronomers analysed the special 'spectral fingerprint' of the galaxies to identify the motion inside them.
"These kinds of measurements have typically only been done on galaxies that we see about three billion years after the Big Bang - a completely different epoch of time," Renske Smit, also from Cambridge, told IBTimes UK.
"This will make it possible in coming years to study the physical processes that form the first galaxies in a whole new way."
The researchers were also surprised to discover that the two newborn galaxies they observed were not as chaotic as expected.
According to Smit, at this stage in the universe's evolution, gravity caused gases to flow rapidly into galaxies, essentially stirring them up and causing the formation of lots of new stars – many of which exploded violently.
So when the researchers discovered the newborn galaxies it was thought that they would be messy and disordered. They found, however, that the new galaxies were relatively well-regulated and more similar to our own galaxy than expected.
Billions of years to evolve
"These galaxies have had much less time to evolve and grow because we see them at 6% of the current age of the universe while our own Milky Way has had billions of years more time to evolve," Smit said.
"They are also about five times smaller and 10 times less massive than the Milky Way.
"However, the fact that we see rotation in the gas of these galaxies suggests that they are already much more similar to the Milky Way than we would have expected. So potentially some of the earliest galaxies, like the ones we have seen in this study, evolve very rapidly immediately after they are born."
It is difficult to make observations of the early universe because during this period it was filled with a 'haze' of hydrogen gas which obscures the view of optical telescopes.