This story is excerpted and adapted from Egill Bjarnason’s How Iceland Changed the World: The Big History of a Small Island, published in May 2021 by Penguin Books. Two years before making history with one small step onto the Moon, Neil Armstrong went salmon fishing in northern Iceland. A picture of him, standing by a river, is exhibited in a regional museum, but the image is so small that at first you might assume it’s just a regular snapshot of recreational life in the 1960s. Smiling faintly as he holds…