At first glance, the astrophysics department at the University of Bristol doesn't seem like the sort of place where anything extraordinary happens.

The quiet, rather old-fashioned corridors have all the trappings of dusty academia. Names of professors on doors. Notice boards heavy with all the pinned up student memos for the new term. Flickering fluorescent lighting.

But here, hidden deep in this thoughtful world, something extraordinary has been happening – something that will bring new meaning to the expression "distance learning".

For it is here, in these quiet offices, with windows overlooking the Bristol sprawl, that two academics have had their focus fixed firmly on the distance over the past few years.

In fact, Professor Malcolm Bremer and Dr Ben Maughan have been concentrating their expertise on some of the farthest known objects in the universe.

Separated only by a ramshackle staircase, these two men have been working on some of the most mind-blowing studies imaginable.

Downstairs, Dr Maughan, 31, has been fixing his gaze 10.2 billion light years away. One light year is equal to about 5,878,630,000,000 miles. He's been working on an international project to study the most distant galaxy cluster yet detected.

The network of galaxies was spotted by combining data from NASA's Chandra X-ray Observatory with data from optical and infrared telescopes.

The epic formation is more than a billion light years further into space than the most distant cluster previously known. It is so distant, that the time it has taken for its light to reach us here on Earth, means we are actually observing it as it was when the universe was only a quarter of its present age.

This means that Dr Maughan is not only looking beyond the wildest dreams of most scientists, he's also looking back in time.

The galaxy cluster, known rather unromantically as JKCS041, was originally detected in 2006 in a survey from the United Kingdom Infrared Telescope.

The distance to the cluster was then determined from optical and infrared observations from the Canada-France-Hawaii telescope in Hawaii, the European Organisation for Astronomical Research in the Southern Hemisphere's wonderfully titled "Very Large Telescope", and NASA's Spitzer Space Telescope.

Infrared observation is important because the optical light from the galaxies at large distances is shifted into infrared wavelengths as a result of the continual expansion of the universe.

Galaxy clusters are the largest gravitationally-bound objects in existence. Finding such a large structure at this very early epoch will reveal important information about how the universe evolved at this crucial stage.

Dr Maughan analysed the Chandra X-ray data that proved to be the final – but crucial – piece of evidence, showing that JKCS041 was, indeed, a genuine galaxy cluster.

"The extended X-ray emission seen by Chandra shows that hot gas has been detected between the galaxies as expected for a true galaxy cluster, rather than one caught in the act of forming," he explains.

"This discovery is exciting because it is like finding a Tyrannosaurus Rex fossil from right at the point that T-rex first evolved."

JKCS041 is found at the cusp of when scientists think galaxy clusters can have existed in the early universe, based on how long it would have taken them to assemble. The experts don't believe gravity could have worked fast enough to make galaxy clusters much earlier.

Studying its characteristics – its composition, mass, and temperature – will therefore reveal more about how the universe took shape.

Dr Maughan has worked at Bristol for two years – he was previously at the Harvard- Smithsonian Center for Astrophysics in Massachusetts.

He says he was thrilled to be given the opportunity to work on this extraordinary project.

"When your big passion in life is studying distant galaxy clusters, to get the chance to work with the data from the most distant galaxy cluster ever discovered, is tremendously exciting," he says.

But upstairs, Professor Bremer has had his focus even further into the epic distance.

Somehow it seems that there's an intensity in his gaze that must only come from looking further into the universe than anyone before. Either that, or perhaps it comes from trying to explain the almost inconceivable theories to Bristol's students for the past 11 years.

Recently, Professor Bremer has been studying a phenomenon known as "gamma ray bursts", and one gamma ray bust in particular, GRB 090423.

If, like me, you're not well up on your individual gamma ray bursts, what you need to know is that GRB 090423 is the most distant single object ever observed by man.

As a journalist, it's tempting to use the lazy expression, "the edge of the universe", but Professor Bremer is quick to point out that the universe doesn't have an edge (please don't ask me to explain this one, but take his word for it).

My use of the word "object" is also clumsy. Far from being an object, the gamma ray bust is an example of the brightest and most violent explosions known to have existed.

"The explosion is thought to accompany the catastrophic death of a very massive star as it ended its life," Professor Bremer explains. "It is triggered by the centre of the star collapsing to form a black hole.

"Only not all the material from the star gets consumed by the black hole. Instead it emits a burst of gamma rays into the universe.

"Normally things this far away would not appear this bright. It's a quirk of the fact that the gamma ray burst was pointed straight towards us, that we are able to see it with such intensity.

"Indeed, if you had been looking at the right part of the night sky a year ago, you might have seen a flash of light with the naked eye from one of these bursts."

Although the glow of the explosion has now died away, Professor Bremer and the astrophysics community can continue to learn from it.

"By observing such a distant object, we can gain some further insight into the conditions in the universe at this very early time in its evolution," he explains.