Oldest Galaxies Discovered on 'Our Cosmic Doorstep'

Some of the oldest galaxies to be discovered in the expansive Universe are right on our cosmic doorstep, according to a study published Thursday in the Astrophysical Journal.

Researchers from the universities of Durham and Harvard explained that these nearby galaxies formed more than 13 billion years ago, which was just a few million years after the Big Bang, according to BBC.

In fact, these galaxies are so old they are believed to have contained some of the first stars to have formed.

This discovery is about as exciting as coming across the earliest human remains, said Professor Carlos Frenk from the U.K.'s Durham University, in a statement.

"Finding some of the very first galaxies that formed in our Universe orbiting in the Milky Way's own backyard is the astronomical equivalent of finding the remains of the first humans that inhabited the Earth. It is hugely exciting."

Frenk explained that these findings support the current model of evolution of our Universe.

Cosmologists believe that the very first atoms formed when the Universe was about 380,000 years old. These atoms, which gathered into clouds, eventually began to cool and settled into small clumps of dark matter that emerged from the big bang.

During this cooling down phase, which is known as the cosmic dark ages, the gas inside the dark matter, or "halos," grew unstable and began to form stars, which are viewed as the first galaxies to ever form.

Two populations of galaxies orbiting the Milky Way were identified by the research team.

One features galaxies that formed during the cosmic dark ages and the other comprises of galaxies formed hundreds of millions of years later.

"For some of these tiny satellites, maybe 50 percent or even 90 percent of their mass was assembled at a time when the Universe was less than one billion years old," lead author Dr Sownak Bose, from the Harvard-Smithsonian Center for Astrophysics in Cambridge, U.S., told BBC News.

Dr Alis Deason, who is a Royal Society University Research Fellow at the ICC, said in a statement that "this is a wonderful example of how observations of the tiniest dwarf galaxies residing in our own Milky Way can be used to learn about the early Universe."

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