How to manage the heritage values of space junk

'My career as a heritage consultant working with engineers on mining, urban development and construction projects was a huge influence on how I started to think about the heritage values of space junk. It was no good being too theoretical and rarified: my approach had to be practical.

Doing the research to work out if space junk might be culturally significant was almost the easy part. There’s no doubt that many, many satellites, like Vanguard 1, Australis Oscar 5 and Syncom 3, are bursting with significance, and this is without considering the fragments and broken bits.

Artist's impression of the Vanguard 1 satellite, in orbit, with Earth below it.
Credit: unknown 

In the field on Earth, there were many situations where I had to persuade an engineer (who was just trying to do their job) that the route of a power line or some other infrastructure might have to change to avoid a place of significance to the Aboriginal or European community. I had heritage legislation to back me up. There’s no similar system for space.

It was very common for developers to leave the heritage survey until the last minute, because they assumed it was less important than project design. But by the time a road alignment, for example, had been chosen, there was often very little room to manoeuvre if it turned out that significant heritage was lying in its path. Changing the road would be very expensive at late stages in the design. I’ve had countless conversations in my career with developers grumbling at the expense of heritage assessments, as if it were the fault of the heritage. ‘If you’d started this process early,’ I’d say, ‘it wouldn’t be the big cost it is now.’ Planning was the key to spending as little money as possible – which was very persuasive to developers and engineers.

The other key factor was persuading people that culturally significant space junk should not be removed from its natural setting in orbit – which would be very expensive, if necessary at all. I considered the risk of collision to see just how dangerous some of these significant old satellites might be to functioning spacecraft. Spacecraft with fuel and power can move out of the way of a piece of rogue space junk.

There are also hit lists of the most dangerous junk, usually old rocket bodies abandoned in orbit which are likely to explode. It would be very useful to have a heritage list of significant satellites in orbit. If a heritage satellite appears in a conjunction analysis or space junk hit list, then we can think about how to manage it. For the moment, there’s nothing we can do'.

Excerpt from Dr Space Junk vs the Universe: Archaeology and the Future  (UNSW Press, 2019, pp 123-124)

Things seen from space: the Great Wall of China

It's quite a claim to make: that such-and-such a 'man-made' thing can be seen from space. The one people are probably most familiar with is the Great Wall of China. There's a rumour that Yuri Gagarin saw it during his epic first orbit of the Earth in 1961. There's also a popular culture myth that it's visible from the Moon.

The Moon story, is, interestingly, pre-Space Age. In the 16th and 17th centuries, Portuguese travellers brought accounts of the Great Wall back to Europe, so people there became aware that this impressive structure existed. 

In 1754, the Reverend William Stukeley, who was one of the first people to study Stonehenge and hence somewhat of an expert on large structures, mentioned the "Chinese wall, which makes a considerable figure upon the terrestrial globe, and may be discerned at the moon" in a letter. (Stonehenge really wasn't of much interest to the English public before Stukeley). 

In 1895, English journalist and MP Henry Norman made the same claim: "Besides its age it enjoys the reputation of being the only work of human hands on the globe visible from the moon." He had at least traveled in China and seen the Great Wall first hand. But he doesn't give any evidence to back this claim up. The debate around canals on Mars in the late 19th century may have made it seem logical that long linear artificial structures would be visible from other planets.

In the 20th century, human eyes went to space for the first time. They were in Yuri Gagarin's head.  But he did not mention the Great Wall at all. 

Of course, it's all relative. Whether it's visible or not depends on where your orbit is, whether it's day or night, and what you are looking with. In general I think people mean visible with the unaided human eye, or with satellites in Low Earth Orbit. Higher up in the orbital column, satellites aren't looking. In certain limited conditions, the Great Wall can be seen by astronauts on the ISS or by Earth observation satellites.

The Great Wall seen by ESA's Proba satellite in 2004. Credit: ESA

There are, however, other human structures which are visible from space, including:

• Dubai's palm islands - these are artificial islands built as residential complexes off the coast of Dubai, in the shape of palm leaves
• Major cities at night - when illuminated, the largest cities are easy to pick out as distinct entities. 
• The Pyramids at Giza - located in Egypt, the Great Pyramid of Giza was one of the seven wonders of the ancient world. It's astonishing to think that it's retained this significance with a new space age spin. The three pyramids at Giza are not visible to the naked eye, but can be seen through a space-based camera.
• The greenhouses of Almeria - 64, 000 acres of greenhouses in Spain. These are visible through cameras because the reflective material of the greenhouses catches the light in daytime. 
• The Bingham Canyon Mine - this open-cut copper mine is the largest human excavation in the world. It extends over 4 km and is over 1 km deep. 

I don't think anything has been designed with the specific aim of being seen from space - yet.

This is Earth taken from lunar orbit - the famous Earthrise photo of 1968.
No human-made features visible. Credit: NASA

From another perspective, it's not just the human artefacts that are visible. It's the impacts of human activities, such as forest loss, desertification and the creep of agriculture. These are also human things seen from space.

Why am I interested in this? 

Firstly, things seen from space may tell us something about what to look for as signs of intelligent life on exoplanets. This is one of the goals of SETI research. 

On the other hand, there are a bunch of people who look for alien structures on the Moon and Mars using remote sensing imagery from orbiting spacecraft, just like archaeologists do to locate and map artificial structures on Earth - and, apparently, they find them!. It comes down to what looks natural and what looks cultural, and this is often because something resembles an Earthly structure. This is called pareidolia, the phenomenon of seeing patterns where none exist.

But here's the real reason. Although you won't find it mentioned in the World Heritage listing, the myth of being visible from space contributes to the heritage value of the Great Wall of China. It is about aesthetic and social value, at least to people in the 'west'. 

The aesthetic value of the Great Wall is about scale - something so long, that required huge amounts of labour over centuries in its different forms (I'm not going to go into it's complex history). It's a stable landscape feature, 20, 000 km long. In 1644, when it's construction finished, it was the world's largest military structure. It follows the top of a ridgeline, so it is visible from a distance. To say that it can be seen from space is a testament to its sheer size and ambition. 

Being seen from space is really a statement about human perceptions of things so large that our eyes can't take them all in at once, that their true form is not comprehensible from the ground. The Nazca lines are like this too. It's about things so enormous from a human scale that they seem almost inhuman. Unlike the Great Pyramid at Giza, though I don't think anyone has claimed that the Great Wall was made by aliens. 

Hold my beer, it seems that they have.

The social phenomenon is about people's beliefs about space. It's like space-flown objects, which are held in museum collections and fetch high prices in the collector's market: the special relationship with space adds value. They could be the most boring, mundane object or material, but when they've come back from space they take on almost magical qualities. They're a talisman, a touchstone, something that brings you spatially closer to that unattainable place (for most of us).

In the 1980s. Frank White put forward the idea of the Overview Effect. The Overview Effect is a semi-mystical experience that involves seeing Earth as a whole planet, a natural object on which human traces are insignificant. The planet is fragile and beautiful, and its delicate ecological balance could be destroyed by human actions. The people of Earth should be united, not torn apart by wars and conflicts: national boundaries are not visible from space. (Although having said that, South Korean astronaut Soyeon Yi reports her sadness at seeing the very obvious differences between North and South Korea when lit up at night - that was a national border visible from space).

This is a different form of the Overview Effect, which involves seeing instead the stability and resilience of human culture, its ability to take raw telluric materials and build them into a human signature on the planet: mark the planet as cultural rather than natural, when seen from space. And potentially when seen by outsiders approaching from space, seeking the evidence of sentient actions. (There might be a few clues before then. I talk about this in 'The Abandoned Solar System')

This brings us to the concept of Outstanding Universal Value, which is the basic criterion for achieving World Heritage status. A natural or cultural place has to have heritage value potentially for the entire human species. It's a big call. But if any cultural feature could be said to have it, it would be something so monumental it could be seen from space - by us, or by another species.

And: at some point in the future, we may have to consider what it means if human-made structures or environmental impacts are visible on the Moon, from Earth.

References
The Family Memoirs of the Rev. William Stukeley (1887) Vol. 3, p. 142. (1754)

Norman, Henry 1895 The Peoples and Politics of the Far East, p. 215.

The Declaration of the Rights of the Moon

 

We the people of Earth -

Acknowledging the unique, intact, interconnected lunar environments and landscapes which exist on the Moon;

Acknowledging the ancient, primordial relationship between Earth and the Moon;

Mindful of how much is still unknown about the co-origins of Earth and the Moon;

Aware that the Moon is critically important to the healthy functioning of the Earth System, and is a vital sustaining component of all life on Earth;

Aware that the Moon holds deep cultural and spiritual meaning for human beings;

Acknowledging that the cycles of the Moon have enabled life itself to evolve on Earth;

Mindful of the immeasurable value the Moon holds as a repository of deep time and connection among all beings who have ever lived on Earth, since its features have remained almost unchanged since time immemorial;

Conscious that wealthy nations and corporations are developing technologies that may make it possible to return to, live on, mine and otherwise alter the Moon;

Aware of humanity’s impact on the Earth - causing ecosystem collapse, a new era of mass species extinction and global climate change - and seeking to avoid destruction and change to the natural systems and ecosystems of the Moon,

Declare that -

1. The Moon – which consists of but is not limited to: its surface and subsurface landscapes including mountains and craters, rocks and boulders, regolith, dust, mantle, core, minerals, gases, water, ice, boundary exosphere, surrounding lunar orbits, cislunar space – is a sovereign natural entity in its own right and, in accordance with established international space law, no nation, entity, or individual of Earth may assert ownership or territorial sovereignty of the Moon.
2. The Moon possesses fundamental rights, which arise from its existence in the universe, including:
• (a) the right to exist, persist and continue its vital cycles unaltered, unharmed and unpolluted by human beings;
• (b) the right to maintain ecological integrity;
• (c) the right to be defined as a self-sustaining, intelligent, cohesive, intact lunar ecosystem, beyond current human comprehension;
• (d) the right to independently maintain its own life-sustaining relationship with the Earth’s environments and living creatures; and
• (e) the right to remain a forever peaceful celestial entity, unmarred by human conflict or warfare.

Background

The Moon has been a constant feature of human existence since the time of our earliest ancestors, illuminating the night, regulating cultural activities, and inspiring science, knowledge and belief.

Since the development of the technology to travel into space over 80 years ago, the Moon has also come to be regarded as a resource for use by humans. International space treaties such as the Outer Space Treaty of 1967 proclaim that the Moon is part of the common province of humanity and not subject to territorial claims. Nevertheless, space agencies and private corporations are proposing to extract lunar resources for profit.

There are many legal and ethical complexities around lunar mining but underlying them is the common space community belief that the Moon is a dead world toward which we have no moral obligation. This view is at odds with public beliefs about the cultural and natural significance of the Moon. It also contrasts with a growing movement on Earth recognising the rights of nature, which has seen entities such as the Whanganui River in New Zealand granted legal personhood. There is mounting scientific evidence that the Moon has dynamic ongoing geological and cosmic processes. Given the acceleration of planned missions to the lunar surface, it is timely to question the instrumental approach which subordinates this ancient celestial body to human interests.

A few years ago, landscape architect Thomas Gooch, Director of the Office of Other Spaces, started running public forums to discuss how we should understand our relationship with the Moon, as part of his work with the Moon Village Association (MVA), an international NGO based in Vienna. The MVA is committed to ethical and sustainable engagement with the Moon. The last of these forums, in August 2020, considered whether the Moon could be granted legal personality as a way to acknowledge that the Moon had an existence of its own separate from human perceptions. Watch the recording of the forum below.

The forums led to a discussion between Dr Michelle Maloney (National Convenor, Australian Earth Law Alliance), Ceridwen Dovey (space researcher and writer), Alice Gorman (space archaeologist), Mari Margil (Executive Director of the Center for Democratic and Environmental Rights, US) and Thomas Gooch, about creating a Declaration of the Rights of the Moon. One issue was clear: as the Moon held such importance for the people and non-humans of Earth, it was imperative to consult widely and gain as much input as possible. However, there had to be some starting point to open the discussion. Slowly the idea that the group would draft such a declaration was born.

Over the course of a year, the group met regularly to define and refine the necessary concepts. The Draft we have created here is the end result. But it’s really just a beginning – a way to start the discussion at a global level. We don’t know how this declaration will evolve, but your participation is a key part of the process.

In the 1870s, Flaubert predicts space travel by balloon

'BALLOONS: With balloons, we'll end up going to the moon. We're not about to control them.'

Gustave Flaubert, Dictionary of Received Ideas (1870s)

Illustration, "Blanchard's Balloon" from Wonderful Ballon Ascents, took off on March 2, 1784 near the Ecole Militaire at Champ-de-Mars, Paris, France. Date: 1870. Source: Wikimedia Commons

An archaeological survey of Earth orbit.

Sometimes people say that a problem with space archaeology is that we can't just pop into orbit or to the Moon for a season of fieldwork, and collect data in the usual way. How can you do archaeology without the quintessential archaeological activities of excavation and survey? Aren't we just the much-maligned 'armchair archaeologists'?

In answer to which I give you:

Cartoon by Robert Mankoff. Image courtesy of the New Yorker

There's nothing wrong with a comfy armchair, if you ask me. They're good places for thinking. And cups of tea, with maybe cake too, or a fluffy lamington, or a delicious Iced VoVo, every space archaeologist's biscuit of choice.

The first archaeological surveys in orbit

However, surveys using remote sensing are now standard in archaeology. This involves both geophysical surveys - sending different signals into the ground to detect metal objects, cuts and cavities - and aerial or satellite surveys to locate and map sites, using optical or multispectral data collected from UAVs, aeroplanes or satellites in Earth orbit.

When considered from this perspective, it turns out that archaeological surveys of human material in Earth orbit have been conducted since the beginning of the space age, using antennas and optical telescopes of multitudinous configurations to locate and track spacecraft and space junk. (In orbital archaeology, tracking is the equivalent of mapping a site). Rather than turning a sensor towards the Earth, these eyes and ears look towards the heavens.

The first such survey had two artefacts as its target - Explorer 1 and Sputnik 1 in the International Geophysical Year of 1957-58. You could say that this was the turning point, when space ceased to be a purely 'natural' environment and became a cultural landscape. First it was just the one satellite, a small blip for three months. Sputnik 1 orbited from 4 October 1957 to 4 January 1958. Between 4 October and 3 November when Sputnik 2 was launched, Sputnik 1 was the only artefact of its kind in all the solar system - just think of that! 

The survey team, if we can call it that, consisted of human and mechanical observers. The human observers were the volunteer brigades of Project Moonwatch. The brainchild of Professor Fred Whipple of the the Smithsonian Astrophysical Observatory, the Moonwatchers were teams established in 27 countries to look for and visually track the first satellites. Patrick McCray has written a wonderful book about them.

The mechanical observers were the antennas and cameras set up just to look for satellites. There were the Minitrack interferometers, of which there were 14 across the US, South America, South Africa and Australia. The Smithsonian Astrophysical Observatory set up a network of 12 Baker-Nunn cameras, not just for satellites but also natural objects in Earth orbit. The cameras were located in Argentina, Curacao, India, Iran, Japan, Peru, South Africa, Spain, US and Australia - where Woomera was one of the few locations to have both a Minitrack and a Baker-Nunn.

The USSR KIK network was developed from the ground tracking stations of the R-7 rocket, an intercontinental ballistic missile that was the launcher for Sputnik 1. There were 13 ground stations, all within the USSR. Now this is an interesting point, because the Vanguard satellite project was designed explicitly to disguise its military origins; hence their tracking network was not simply an adaptation of a defence one. The USSR was not so concerned about 'military taint'.

On 31st January 1958, Explorer 1 poked its head above the ionosphere and joined Sputnik 2. Just the two of them. Vanguard 1 was launched on St Patrick's Day on the 17 March, and then there were three. A bit less than a month later, Sputnik 2 re-entered on 14 April, and it was down to two satellites again. All that infrastructure for two little blips in the sky.

Sieving the sky

Since that time, the number of instruments surveying the sky for human artefacts has increased exponentially, as have their targets. It's not just whole satellites any more; it's also the fragments, of which there are millions. In fact, you could say that the tracking instruments are like the nested sieves archaeologists are accustomed to use in excavations. Usually, you screen the dirt through a top mesh which is 5 or 7 mm. This catches the larger artefacts. Beneath it is a smaller mesh, usually 2 mm. This catches the smaller pieces. Everything else falls through and becomes part of the spoil heap. If you use even smaller sieves, or flotation tanks, you can recover pollen and other microscopic objects.

This is very like how observation of space junk from Earth happens. Most of the optical or radar tracking instruments can only 'see' pieces 10 cm or above. This is the top sieve. Others can 'see' smaller pieces - these tend to be lasers, or beam park instruments. This is the 2 mm sieve.

The analogy is even more apt when you consider that artefacts larger than 5 mm can slip through the top mesh, depending on their angle. Angle and cross-sectional area are also factors in how visible a bit of space junk is from the ground.

In archaeology the artefacts are often fragments, or by-products of manufacture. Sometimes we piece the bits back together to form a whole stone tool, or a ceramic vessel. Sometimes we use them to calculate the weight of a particular material in that excavation unit. For your edification, I can tell you that the weight of human material in Earth orbit is the equivalent of 10 million cane toads.

You could divide space objects into active and passive. The artefacts we excavate from the ground don't usually tell us where they are. If you're using a magnetometer, though, metal artefacts will reflect a signal back to your instrument above the ground. This is a passive signal. Functioning satellites are not your usual artefacts, in that they're often actively emitting signals that you can tune into.

Robot archaeologists

Terrestrial space object tracking could be recast as a kind of archaeological survey. But imagine an archaeological survey of orbital space done remotely using cameras mounted on other spacecraft. There are a few companies, such as HEO, who are imaging spacecraft on-orbit. 

The International Space Station, taken from orbit. Image courtesy of HEO

Does thus change our perception of what orbital debris is? Of course you would need a robust optical sample, and there are still many limitations of these camera surveys. 

All of this is just to say the inability to do fieldwork in space does not invalidate us as archaeologists, and indeed gives the discipline a deeper lineage. Using remote sensing to collect archaeological data has a long history. So does using remote sensing from Earth-based instruments to survey the sky - including human artefacts.

References

Bonnal, Christophe 2025 The proliferation of space debris in Earth's orbit. Polytechnique Insights 12 February

Centre for Invasive Species Solutions (2012) Overview of the cane toad. Factsheet. PestSmart website. https://pestsmart.org.au/toolkit-resource/overview-of-the-cane-toad accessed 06-09-2025

Lavatime: day, night and dreams in a lunar lava tube (excerpt)

This is the opening four paragraphs of a short story, which was shortlisted in the 2024 Minds Shine Bright Light and Shadow international literary competition. The story is about how the protagonist lets go of Earth and commits herself to the Moon, with some nefarious activity along the way.    

Lavatime

    Waking up on the Moon was a process of adjustment. Sleep was such a terrestrial phenomenon, she had decided. In the transition before her eyes opened, she always felt herself to be still ‘at home’, in the Earth bedroom, the Earth bed with the pale green satin quilt that no longer existed. It was a moment of disorientation before she became fully conscious of where she was. 

    The residues of bright trees fled from her dreams. She could set her room’s ‘window’ to show any view she liked from Earth — such earthly connections were held to be beneficial for the mental health of the lunarians — but somehow these digital forests seemed less real than the trees formed solely inside her sleeping brain. Hers were usually eucalypts with long glossy leaves and piebald cream-and-brown trunks. Sometimes the hum of insects hung in the leaves, barely leaving an imprint in her mind as the regular morning sounds of the lunar habitat started to overwrite them. 

    So she did not usually turn the window on to Earth. She preferred the live feed to the surface. Not many of her colleagues did, she knew; but somehow this made the Moon real for her, stabilising her here. The unchanging, silent, grey surface was an anchor to a reality that grew further and further away from Earth the longer she stayed. 

    The surface was never as still or boring as the others believed, though. Over 15 Earth days, the angle of the sunlight slowly changed, and she saw the plain, strewn with rough boulders, reveal different contours and textures to her gaze. It was quite dynamic really, if snail-slow in its progress sometimes. Time was such a moveable feast on the Moon. Inside the lava tube, they worked to a local clock which matched circadian rhythms, aided by artificial light and dark; they communicated with Earth using UTC; and they pitted themselves against the implacable force of the long lunar day, which would have frozen them in its dawn and boiled them at its noon. Of the lunar night they did not speak.

Lava tube entrance. Image credit: NASA / Goddard / Arizona State University

Reference 

Gorman, A.C. 2025 Lavatime. In Amanda Scotney (ed) Light and Shadow. Minds Shine Bright International Creative Writing Anthology Seasons 2, pp 109-114. Windsor, Vic: Minds Shine Bright

Purchase a copy here.

Acknowledgements

I'd like to thank Amanda Scotney for tracking me down when I was ill, and including me in the public events around the anthology, and my esteemed colleague Lynley Wallis for providing valuable feedback and encouragement!

What is space archaeology?

I made a little, very amateurish, animation explaining what space archaeology is.