This photograph capturing light 1500 years old was taken by pioneering photographer and astronomer David Malin (Image: David Malin)

Every astronomy buff is familiar with the Horsehead nebula in the constellation Orion – a dark, dense molecular cloud in the shape of an equine head and neck, silhouetted against the fiery light of ionised hydrogen gas. The optical effect is completed by the less often appreciated “mane” behind the horse’s head (pictured right).

The mane is a cloud of cold gas, mostly hydrogen, that is fluorescing. Since this fluorescence is red, David Malin used a red filter to take …