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"I remember seeing this on a sky survey and saying, 'wow look at that!'" says astronomer Paul Hickson, from the University of British Columbia in Canada, who rediscovered the group in 1982.

"All that I was using at the time was a big plastic ruler and a magnifying glass while looking over sky survey prints

Studying densely packed groups like this – all five galaxies in this image would fit inside two Milky Ways – helps astronomers to understand the where and the when and the how questions surrounding galaxy formation.

That will eventually lead to their merger, and scientists think dark matter could be playing a part, forming a cloud around the galaxy group and slowing the individual galaxies down.