Asked by: Adam Perkins, Exmouth
The face-like pattern of light and dark on the full Moon is a classic example of pareidolia, in which our minds conjure up familiar objects from random shapes. In the case of the Moon, those shapes take the form of the so-called ‘maria’ (from the Latin for ‘seas’), such as Mare Tranquillitatis – the Sea of Tranquillity, where Apollo 11 landed almost 50 years ago.
In reality, these ‘seas’ are vast plains of relatively dark lava that spewed out of the Moon’s interior when it was still molten. The sheer antiquity of the maria was one of the most startling discoveries to emerge from studies of the rock samples brought back by the Apollo missions, which showed that the maria are typically around 3.5 billion years old. In other words, the Man in the Moon we see today has looked down on the Earth since long before complex animals emerged around 500 million years ago.
Robert is a science writer and visiting professor of science at Aston University.