A long time ago in a galaxy far, far away – that’s how far back in time the Hubble telescope has seen, shattering the previous cosmic distance record set by astronomers.
Scientists pushed the space telescope to its limits to confirm that the galaxy is 13.4 billion light years away, making it the most distant and oldest object known in the universe.
The light we see from the galaxy began its long journey through space just 400 million years after the Big Bang gave birth to the universe, thought to have happened around 13.8 billion years ago.
Astronomers measured the distance to the galaxy, known as GN-z11, by splitting its light up into its component colours.
Because of the expansion of the universe, distant objects flying away from us have their light stretched to the red end of the spectrum – a phenomenon known as “red shift”. The larger an object’s red shift, the further away it is.
Previously a galaxy called EGSY8p7 held the red shift record with a figure of 8.68. But GN-z11 has a red shift of 11.1, corresponding to just 400 million years after the universe began.
Dr Pascal Oesch, a member of the team from Yale University in the US, said: “We’ve taken a major step back in time, beyond what we’d ever expected to be able to do with Hubble. We managed to look back in time to measure the distance to a galaxy when the universe was only 3% of its current age.”
GN-z11 is believed to be 25 times smaller than the Milky Way, but growing fast and spawning new stars 20 times faster than our galaxy.
The findings, reported in the Astrophysical Journal, raise many questions because according to current theories of cosmic evolution even a galaxy of this size should not have existed so long ago.
Co-author Dr Ivo Labbe, from the University of Leiden in the Netherlands, said: “The discovery of GN-z11 showed us that our knowledge about the early universe is still very restricted. How GN-z11 was created remains somewhat of a mystery for now. Probably we are seeing the first generations of stars forming around black holes.”
Space is pretty cool, huh?