Astronomers Discover Most Distant Galaxy To Date

It's a galaxy far, far away. Astronomers scanning the heavens discovered the most distant known galaxy lying so far away that it gives scientists a look at the universe's infancy.

Galaxy z8-GND-5296 has been dated to just 700 million years after the Big Bang, our universe's moment of conception. For comparison, the universe is estimated to be around 14 billion years old, making this galaxy an ambassador from when the universe was five percent its current age.

"By observing a galaxy that far back in time, we can study the earliest formation of galaxies," said Bahram Mobasher from the University of California Riverside. "By comparing properties of galaxies at different distances, we can explore the evolution of galaxies throughout the age of the universe."

The team of astronomers initially began by poring through Hubble Telescope data and looking for far away galaxies by their color. The process, however, was not accurate enough and the researchers had to rely on spectroscopy instead.

"What makes this galaxy unique, compared to other such discoveries, is the spectroscopic confirmation of its distance," Mobasher explained.

As light travels through the universe, it slowly tends towards the red end of the spectrum due to the universe's expansion, a phenomenon known as "redshift." With the help of the new MOSFIRE instrument on the Keck telescope, the experts were able to determine that galaxy z8-GND-5296 has a redshift of 7.5, higher than the previous record-holding galaxy's redshift of 7.2.

"With the construction and commissioning of larger ground-based telescopes — the Thirty Meter Telescope in Hawai'i and Giant Magellan Telescope in Chile — and the 6.5 meter James Webb Space Telescope in space, by the end of this decade we should expect to find many more such galaxies at even larger distances, allowing us to witness the process of galaxy formation as it happens," Mobasher said.

You can read the full published study in the journal Nature.