Some of the most dramatic and awe-inspiring images of outer space, are those that originate from the Hubble Space Telescope.
These images are published by a group of dedicated astronomers and image processing specialists called “The Hubble Heritage Project“, who, since 1998, have released a new image almost every month.
But according to Elizabeth Kessler, Assistant Professor of Art and Liberal studies at Ursinus College in Collegeville, Pennsylvania, it’s important to look at the cultural and aesthetic construction of the Hubble images, which tells us as much about the culture that created them, as it do about the nature of deep space.
Most people do not realise, that the raw data received from the Hubble Space Telescope looks nothing like the dramatic views that are released by the Hubble Heritage Project.
For a start, the original data is in black and white, streaked with white lines, and features elements that are invisible to the naked eye. In order to emphasise specific aspects of this data, (including the invisible elements) much licence is taken in interpretation, and many subjective decisions are made about composition, colour and contrast.
The result of these decisions bears a striking resemblance to the great 19th century Frontier Artists of the American west .
Artists like Albert Bierstadt and Thomas Moran, who were attempting to portray a world beyond the frontiers of human existence. And this involved more than just appearance. In the same way that Romantic artists like Bierstadt and Moran used the landscape to evoke feelings of awe and wonder – to experience what Immanuel Kant called the “sublime” – the Hubble Project image processing specialists now seek to create a similar response with these amazing images… presenting cosmic clouds of gas and dust in the same way as dramatic landscapes found on Earth.
Scale and orientation are matters of interpretation. Cardinal directions aren’t relevant for an orbiting telescope, and astronomers can choose how to present the astronomical objects to great dramatic effect. Observations of nebulae, huge pillars of gas and dust, are often oriented such that the pillars rise toward the top of the frame. The light often appears to stream down from above.
It is not hard to imagine something like the Eagle nebula as a detail of Thomas Moran’s Cliffs of the Upper Colorado River, Wyoming Territory.
The use of colour is equally subjective.
The Hubble produces monochromatic data, and astronomers assign colours to three different filtered views to create the now-familiar vivid hues. While the colour choices often have scientific meaning, it’s also worth considering the cultural meanings.
One of the more popular approaches to colour results in images with a blue background and nebulae in shades of yellow, orange, and brown. This tends to create images which bear a remarkable resemblance to the earthly sky and rocky outcroppings of the American west.
The Hubble images also communicate the great size and scale of the cosmos.
In a view of a star cluster in the Small Magellanic Cloud, alternating bands of dark and light pull the viewer’s eye into the deep abyss. The result is a visual experience of great depth. It’s the same technique Albert Bierstadt used in Storm in the Rocky Mountains, Mt. Rosalie to draw the viewer into the vast valley and then upwards to an impossibility high mountain peak.
While astronomers don’t consciously set out to make Hubble images that look like 19th century landscape paintings and photographs, they do recognise and even encourage the connection. Press releases often suggest a similarity. The physical processes that formed the Eagle nebula were compared with the erosion of buttes in the American south-west. The Cone nebula was described as a “craggy-looking mountain-top of cold gas and dust”. On its website, the Hubble Heritage Project also compares a planetary nebula, NGC 3132, to Grand Prismatic Spring, the largest hot spring in Yellowstone National Park. In both cases, the colours indicate a change in temperature. While the comparison explains physical attributes of the planetary nebula, it also encourages the viewer to see it as a landscape, as both familiar and alien.
The works of Moran, Bierstadt and others symbolise exploration and the frontier. Many of the artists and photographers accompanied scientific surveys of the American west, and their work was used to promote further scientific study of the region. In many ways, the Hubble images have a similar function today. They promise the possibility of new frontiers, new places to discover, new worlds to know.