IT WAS a mystery that had puzzled art critics for almost a century. The French impressionist, Edgar Degas, painted his famous Portrait of a Woman back in 1876. The striking image would later be hung in the National Gallery of Victoria, but even as early as the 1920s it was clear that something wasn’t right.

Beneath the stern-looking expression of Degas’ subject, something was hiding. A discolouration in the woman’s right cheek suggested that the artist might have painted his subject on top of a previous image – but of what?

And here, an unlikely hero steps in to the artist’s tale: Science.

Researchers took Degas’ mysterious painting to the Australian synchrotron: A particle accelerator that produces light billions of times brighter than the sun. And with this powerful light, the group were able to piece together a digital reconstruction of the lost artwork behind the painting.

What they found was the ghostly image of a woman, supposedly a model named Emma Dobigny, who was one of Degas’ favourite subjects in the 1870s.

However he clearly hadn’t been happy with this rendition of the model – the half-finished painting sat in his studio for years before the artist finally gave up and painted over it with the portrait we see today.

Scientific techniques like those used in this case could help to unravel other historical mysteries and piece together long-forgotten stories like that of Dobigny and Degas.

At the UK’s own synchrotron in Oxfordshire, research is currently under way to preserve the artworks of the Dutch masters, including Rembrandt.

Like Degas, many of these artists chose to paint over their former artworks to create new pieces – others found themselves working with stained canvases which required a base coat of white paint.

Unfortunately, many painters used lead-based paint in this process. And over the years, traces of lead have reacted with oils and risen to the surface, creating unsightly white blisters.

Art historians are desperately searching for ways to prevent this, and it seems as though scientists in Oxfordshire may be able to help.

Using advanced techniques, we’re able to track the migration of lead within the painting. And if we can understand how this process takes place, it may be possible to prevent it, thus preserving some of the 17th-century’s most recognisable artworks.

Rembrandt’s paintings date back centuries, but science is helping to unravel mysteries even older. In fact, local scientists are currently endeavouring to read messages hidden within the 2000-year-old Herculaneum Scrolls.

In 79AD, Mount Vesuvius erupted, blanketing the towns of Herculaneum and Pompeii and killing hundreds of people in seconds.

Along with the many lives lost, a library containing teachings from influential scholars like Philodemus and Virgil was also destroyed. But some of the scrolls the library contained somehow survived.

Recovered in the 18th century, the Herculaneum Scrolls are far too fragile to ever unfurl. For the time being at least, the mysteries they contain remain trapped inside.

However, scientists are exploring ways of ‘reading’ the texts using advanced technology. The ink used contains traces of heavy metals and so it’s possible to see which parts of the scrolls contain ink. With enough precision, it may even be feasible to decipher the writing inside without damaging the delicate papyrus.

There are still many mysteries left to discover and stories as yet untold. But as science and technology advances, we’re becoming better able to piece together those puzzles.

We might never know what prompted Degas to paint over his portrait of Dobigny, or how the residents of Herculaneum felt as their town became engulfed, but thanks to science, we can help in some small way to bring those stories to life.