NASA scientists reported Wednesday that the Hubble Space Telescope has found a previously unseen group of primitive galaxies that formed more than 13 billion years ago. That means the seven galaxies were formed when the universe was just 4% of its current age.
“Our study has taken the subject forward in two ways,” said Richard Ellis, an astronomer with the California Institute of Technology. “First, we have used Hubble to make longer exposures. The added depth is essential to reliably probe the early period of cosmic history. Second, we have used Hubble’s available color filters very effectively to more precisely measure galaxy distances.”
The findings come from the deepest look into space that the Hubble Space Telescope has ever taken. Looking deeper into the universe means looking further back in time.
The universe is estimated to be 13.7 billion years old. Since light from the newly discovered galaxies has had to travel the vast distance to Earth, they are being seen as they looked 350 to 600 million years after the Big Bang.
The Big Bang Theory postulates that the universe was created when a tiny, super-dense mass exploded and began expanding, eventually cooling and forming stars and galaxies.
NASA noted that Hubble made its observations of these primitive galaxies during six weeks in August and September.
This latest data tells scientists that galaxies grew steadily over a period of time, supporting the theory that the first galaxies and stars formed gradually, instead of instantly, during a time called the “cosmic dawn.”
The Hubble, launched into orbit on April 24, 1990, has become one of the greatest tools available for the world’s astronomers. For example, it played a key role in discovering that the universe, driven by a mysterious force called dark energy, is expanding at an ever-accelerating rate.
Hubble also has been critical in helping scientists discover that most of the known galaxies in the universe contain massive black holes.
Three years ago, the crew of the space shuttle Atlantis fitted the Hubble telescope with two brand-new instruments, a new computer unit and several repaired instruments during a repair mission.
At the time, NASA scientists said that the telescope was more powerful than ever and more able to gaze toward the edge of the observable universe.
The work done in 2009 was expected to keep Hubble running through 2014, if not through 2016 or 2017.