X-rays reveal Van Gogh portrait

A new X-ray technique has revealed a previously unknown portrait of a woman by Vincent van Gogh, which was painted over by the artist.
The peasant woman's face was hidden behind the work Patch of Grass, completed by Van Gogh in Paris in 1887.
Scientists Joris Dik and Koen Janssens used high-intensity X-rays from a particle accelerator to scan the painting and reveal the face beneath.