As Goodall tells BBC Future, this was long before the era of digital photography, so she had to wait a while before she could see the printed images. “It was couple of months or more before there was a safe way to send exposed rolls to the [National] Geographic for processing, and then another wait while they sent the prints back to Kigoma,” she recalls. “When I saw it, though I did not realise it would become iconic, it did make me think of Michelangelo’s painting of God reaching out to Man.”