A Group of 250 ancient galaxies spotted by Hubble

Scientists are able to peek in to the history around the time of Big Bang, thanks to Hubble telescope. It has spotted a collection of 250 tiny ancient galaxies. The Hubble space telescope has been operating since 1990 and still continues to amaze researchers. A team of astronomers has been using Hubble for discovering this group of dwarf galaxies. Scientists have dated the galaxies to be “only 600-900 million years after the big bang.” This might sound like a very big time scale for us, but is very small when compared to the life span of our universe. What makes these galaxies so interesting is not just their age, but also their faintness. NASA told us that the light from the galaxies took around 12 billion years to reach the telescope.

John Richard, an astronomer working on the project said, “The faintest galaxies detected in these Hubble observations are fainter than any other yet uncovered in the deepest Hubble observations.” The Hubble data is being used by the scientists to study the universe’s early stages. Back in time long ago, the universe was nothing but a thick cloud of hydrogen gas, from which the ultraviolet light couldn’t escape. Slowly this began to clear – this stage is called ‘epoch of reionization’ by the scientists. After it all cleared, the UV light could travel great distances. This phase is called as “the universe becoming transparent to ultraviolet light.”

Some of the galaxies discovered now are expected to be involved in the process. NASA says, “they could be the major actors in keeping the universe transparent.” With this discovery the scientists have been able to determine that the reionization phase came to end after 700 million years of the big bang. The Hubble was started as joint project between the European Space Agency and NASA and isn’t getting any older. Earlier this year, it generated beautiful images of Lagoon Nebula, Twin Jet Nebula and dwarf spiral galaxy. The study on the recent finding of the 250 galaxies will be published in Astrophysical Journal.

Image Source: Nasa.gov