The 'Blue Marble' representing planet Earth

The photograph widely known as 'Blue Marble' was taken on 7 December 1972 with a Hasselblad camera during the Apollo 17 mission. It depicts the Earth from a distance of about 45,000 kilometres. In contrast to previous photographs, this one captures the entire planet without being partially in shadow at night, as the sun was behind the photographer. This has significantly contributed to its iconic status and widespread use as one of the most popular photographs in human history, including its diverse and powerful effects. The iconic status of both the photograph and the representation derives from three essential aspects: it conveys the spherical shape of the Earth, shapes our understanding of it as a whole, and makes its manifold value recognizable. Pythagoras and Aristotle already postulated the spherical shape of the Earth and deduced it from experiments, respectively. Later on, globes and maps were produced as models of the Earth in elaborate surveying and cartographic processes, which are based on a high degree of abstraction and were initially only accessible to a limited audience. This only changed with space exploration, allowing astronauts to perceive the Earth as a geometric object in its spherical form. The photograph 'Blue Marble' made this impression accessible to a wide public. While it does in a strict sense not yet provide evidence of the spherical shape, the shape of the geometries on the Earth's surface suggests a spherical shape and makes it perceptible to the senses. The Blue Marble depicts the Earth as a whole. It is depicted in its entirety and surrounded by void space, thus emphasizing wholeness while individual parts recede into the background. The photograph does not show the Earth as an assemblage of numerous parts but as our place in the universe. We are earthlings who live and manage the planet. The variety of bright colours in the photograph lets us refer to life on Earth in its diverse forms, as we are familiar with the many different colours life can have from school lessons and the media. Although reference can be made to individual areas and climate zones, it is ultimately the entirety of this variation that is perceived. Finally, the Blue Marble symbolizes the value of the Earth. Not only is the diversity of life on Earth visible but also the contrast with the black colour of void space. This is no coincidence but the result of planned action, as the original dark grey has been transformed into black through image processing. This contrast between the Earth and surrounding void space makes the Earth appear small and vulnerable. This is contrasted by the impression of the Earth's controllability, as its small size pretends that we can analyse and control the Earth in its entirety. The value and iconic status of the photograph is not solely due to its characteristics. Rather, the way it is ubiquitously used has mainly led to its widespread impact and recognizability. It has been printed on journal covers and stamps, applied to T-shirts, and used in commercials and as screen wallpapers. This happens both in the context of the environmental movement and the Earth Day as well as independently of it. The fact that the photograph is used with similar messages regardless of varying contexts further contributes to its iconicity and impact. It is perceived as a culturally central element that receives its message partly through social construction. As a result, we are able to project more meaning into this photograph than would be the case without its widespread use. The Blue Marble makes our planet Earth appear as one place rather than a space in which we can move and spatially relate things. This is due to the fact that the Earth is depicted in its entirety while lacking country borders as usually found on maps. This is further emphasized by the seemingly perfect geometry, achieved by cropping the 6x6 format and placing the Earth at the centre. A decisive factor in the understanding of the Earth as a whole is the possibility of making abstract knowledge about the Earth tangible through photography. Rotating the photograph by 180 degrees, as has been done to align it with existing abstract knowledge, further contributes to this. The photograph was not taken to represent the Earth in the way described. It was created because Apollo 17 was launched out of scientific curiosity and the Earth was photographed for its captivating beauty. The Blue Marble must thus be regarded as a part of the place-making, as the creation and dissemination of the photograph has significantly shaped our perspective of the Earth as our place in the universe. It does not seem far-fetched to assume that the Earth as one place has only emerged in our minds because this photograph has attained such a wide use and iconic status.