It’s worth noting again that astropalaeontology is a separate discipline from xenoarchaeology, as terrestrial palaeontology is from archaeology (although in both cases the fields share a blurry boundary). Archaeological fields are more concerned with cultural remains, which are created by sophonts.

Secondly the term has been used to describe the study of stellar evolution (as an analogy to palaeontology’s study of the evolution of life). See the paper ‘The evolution of the mass-metallicity relation in SDSS galaxies uncovered by astropaleontology’ by Asari et al. You also see terms like stellar palaeontology, or galactic palaeontology used to discuss this kind of research.

Here’s a summary of ‘galactic palaeontology’ from the University of Sydney:

Ultra metal-poor stars are the living fossils of the stellar kingdom. Although elements heavier than Helium only make up a tiny fraction of any star, they have a profound effect on the stellar structure.
Consequently stars born when the universe was substantially younger, before heavy elements were formed, should stand out from the crowd exhibiting dramatically different physical and thermal structure — or so the theoretical models tell us. Because these fossil stars are rare and far from Earth, nobody has ever been able to examine one in detail. Until now.

If this stellar use of the term was more common, I’d suggest that astropalaeobiology is the better word to describe the study of extraterrestrial fossils. The biology part would avoid confusion, and it ties in with astrobiology, the most common term for the study of extraterrestrial life in use.

Thirdly, I’ve seen one use of the term astropalaeontology to describe study of the way the evolution of life on earth has been affected by astronomical events. See this 2009 article in National Geographic which discusses the theory that a gamma-ray burst might have caused a mass extinction.

According to Wikipedia, Carl Sagan was the first person to propose terraforming Venus in 1961. Terraforming is, of course, the process of altering a planet to make it earthlike. There are other reasons to think twice about undertaking such a project, but here I’ll consider the cultural side of things.

I’d argue that the cultural significance of Venus for much of human history arose from its brightness in the night sky. That brightness is a product of the planet’s high albedo of 0.65. If the planet’s albedo is preserved, then cultural objections to the terraforming process could be mitigated.

Venus’ status as the second brightest object in the night sky was trumped last year when the International Space Station deployed sufficient solar panels to overtake it. Should its pre-eminence have been preserved? I don’t personally think so, but someone with more reverence for the planet might. I think the fact of its brightness is more important than its rank among celestial bodies visible from earth.

Of course, there may be other cultural objections. We occasionally hear cultural or religious objections to human activity on the Moon, based on beliefs about that body. Furthermore, since the planet Venus has become observable by telescope, its dense cloud layers have themselves gained some cultural significance through conjecture about what they could be concealing.

As it turns out, the albedo of Venus might actually be boosted by terraforming. The creation of oceans, or the seeding of the planet’s atmosphere with reflective materials have both been mooted as methods of reflecting solar heat. Would brightening Venus diminish its cultural value? I think not, that the significance lies in its being a remarkably bright object and not in a particular albedo of 0.65.

At the moment no Earth organisation has responsiblity for protecting space heritage, and no terraforming projects are being put in motion so this is a moot, but interesting point. Is the redness of Mars similarly valuable from a cultural perspective? How about the visibility and regularity of recurrence of bodies like Halley’s comet?

Craig Kalpakjian's proposal for a selenoglyph

Geoglyphs are large-scale drawings on the earth’s surface made by either adding or exposing different-coloured material. Historic and archaeological features such as the famous Nazca lines in Peru, or hill figures such as those found in England are examples. People are still making geoglyphs, including the Marree Man created by unknown artists (or vandals?) in the 1990s, and various works of the Land Art movement of the 1960s and 70s.

A recent story about Japanese plans to send an anthropomorphic robot to the Moon to draw a flag on the surface set me thinking about lunar geoglyphs. That term, like geology is derived from the Greek word for Earth, Ge. Selenoglyphs would be more appropriate, based on the Greek word for the moon, Selene. The discipline of lunar geology is called selenology, for example.

There are already selenoglyphs up there!

In the 1948 Bugs Bunny cartoon ‘Haredevil Hare’, the WWII catchphrase ‘Kilroy Was Here’ is seen scrawled on the side of a boulder – the famous Kilroy by implication having reached the moon first, as usual. Wernher von Braun worried that the Apollo missions might become simply ‘Kilroy Was Here’ events, but he probably wasn’t literally thinking about graffiti. Eugene Cernan proved unable to resist the promise of a message that would survive for geological ages when he wrote his daughter’s initials in the regolith (fellow astronaut Alan Bean has painted a picture of this).

On a larger scale the Soviets celebrated International Women’s Day, March 8, by inscribing figure 8s in the regolith with the tracks of Lunokhod 1 and 2 in the 1970s. It has been suggested that the figure 8s are actually depictions of breasts, which would stand in the tradition of terrestrial geoglyphs like the Cerne Abbas giant.

Artist Craig Kalpakjian has proposed a series of colossal symbols on the Moon (see the image to the right). I’d like to see what Moon landing deniers would say about that. I’m all in favour of such a project – it would be an inspiring reminder of human achievement (although the lights of lunar cities would be more inspiring!). Actually, if our civilisation collapsed, people might think it was selenites attempting CETI … maybe we should inscribe something like the Pioneer plaques, or some tips for rebuilding.

[Update 17 May 2010: I've been doing some more thinking about selenoglyphs and I came up with an idea for a glyph to commemorate and preserve knowledge of the moon landings ... a human foot print.]

In a less-appealing but all too plausible vision of future selenoglyphs, there’s a company called Moon Publicity that is trying to sell a technique for engraving corporate logos on the moon’s surface. This reminded me of the famous Isaac Asimov short story ‘Buy Jupiter’, in which aliens purchase the rights to the king of planets to inscribe it with the slogan “Use Mizzarett Ergone Vertices for health and glowing heat!”

Asimov’s story was simply making use of bathos to create humour. The Moon Publicity proposal is awful – the Moon is the common heritage of mankind, in the words of the Moon Treaty, and using it to inscribe something as ephemeral as this season’s slogan for a relatively short-lived corporation is appalling.

Space heritage is something to consider here. The visible face of the Moon has natural and cultural value to every human being, and making significant – eternal – modifications to that isn’t a step to be taken lightly. I’ve argues something similar previously with regard to Venus, which is known worldwide for its brightness – it is the Morning/Evening Star. I’d suggest then that the albedo of the planet Venus is a treasure of our natural or cultural heritage and that future terraformers might have to preserve that.

Anyway, I’ve wandered away from the subject of selenoglyphics. To conclude, here’s a video from Moon Publicity:

Alien, in this instance, refers to members of any species other than that of the hypothetical xenoarchaeologist.  A human studying martian ruins is a xenoarchaeologist, as is a martian studying human ruins.

The term ‘alien’ always sounds a little pejorative to me (how about non-human person?), but I use it here instead of ‘extraterrestrial’ which could be taken as a spatial designation, and because in the future there could conceivably be terrestrial nonhuman cultures (say, from uplifted animals or artificial intelligences). Despite its connotations, the word ‘alien’ conveys the otherness of the culture to be studied.

If xenoarchaeology is the study of past cultures from species other than one’s own, and if you define ‘human’ in a narrow sense to refer to modern Homo sapiens, then archaeologists who study other hominids are already conducting a sort of xenoarchaeology.

Interpreting human, and perhaps hominid, minds and cultures is one thing, in fact we all do it in our everyday lives. But a special set of skills will be needed to study alien cultures without anthropomorphising them.

See Robert Freitas’ paper Xenopsychology or this article on Astrosociobiology for some reading on studying alien cultures.

I’m put in mind of a concept from the Ender’s Game series by science fiction author Orson Scott Card. In it, he introduces a system of classifying ‘strangers’ called the Hierarchy of Exclusion. Here’s an abridged version from Wikipedia:

• Utlanning (translated: “outlander” or “foreigner”", utlänning in Swedish) are strangers of one’s own species and one’s own culture). An utlanning is a person who shares the observer’s cultural identity.
• Framling (translated: “stranger”, främling in Swedish) are members of one’s own species but from another culture. This is a person who is both substantially similar to and significantly different from ourselves.
• Ramen are strangers from another species who are capable of communication and peaceful coexistence.
• Varelse (pronounced var-ELSS-uh) (translated: “being”) are strangers from another species who are not able to communicate with us. They are true aliens, completely incapable of common ground with humanity. In Swedish, varelse means “creature.”
• Djur (translated as: “slavering beast”): are the monsters. “The dire beast that comes in the night with slavering jaws.” Translated from Swedish, djur means “animal”.

Archaeologists today study utlanning and framling remains. Xenoarchaeologists will study ramen and varelse. I don’t have the books to hand, so I’m not sure whether djur refers literally to animals/monsters or to implacably hostile aliens.

Ramen would include most of the aliens of popular science fiction – the Star Trek and Star Wars universes, for example. For examples of varelse consider the aliens from John Varley’s The Ophiuchi Hotline, Peter Watts’ Blindsight, or the creators of the artefact from Algis Budrys’ Rogue Moon.

It seems to me that the distinction between ramen and varelse is potentially a useful one, at the very least offering shorthand terms for use in discussing aliens – fictional or otherwise.

After it was published this paper seems to have fallen into utter obscurity. It was pure serendipity that led me to stumble across it.

All that I can determine about John Armitage is that he became a Fellow of the Royal Astronomical Society on 10 December 1976[1], and that the paper was also presented at the Second British Interplanetary Society Conference on Interstellar Travel and Communication, 4-5 April 1977.

In it the author argues, as I have, that it seems likely that the number of galactic extinct civilizations is greater than the number of galactic extant civilizations. Armitage makes the distinction that detectable civilizations are only apparently extant, given the relativistic gap between signal transmission and detection.

Armitage describes two linked disciplines: astro-palaeontology and astro-archaeology, the first being concerned with non-sapient life. Astro-palaeontology is of interest to xenoarchaeology (and this blog) when tracing the evolution of sophonts. As Alun Salt pointed out recently, the line between palaeontology and archaeology is blurred, and indeed Armitage illustrates this continuum in his article.

Warning against too-close a reliance on terrestrial analogy, which might blind researchers to other possibilities in studying extraterrestrial sites, Armitage offers the cautionary hypothetical of non-indigenous life forms being introduced to a planet:

The most striking and readily identified example of this condition would be a case involving the sudden appearance of a high technology culture which was completely incongruous with the fossil record and lines of evolutionary development established to be indigenous to the planet.

I’m reproducing in full Armitage’s table of the types of remains that might be discovered:

More recent scholars might suggest a category for postbiological remains, although the last three could be suitable.  Armitage actually does argue for the possible existence of “‘robot civilisations’ which would in a sense be the extension of the intelligence which created them, though the biological organisms had died out.” It’s not clear from this whether he’s referring to sapient machines or automata.

It’s very interesting to see the search for Dyson spheres included. Although the idea of searching for them had been around for 16 years, the context of a space archaeology paper is novel for 1976 I think.

Also of particular interest is this mention of a question astro-archaeology might ask: “Do the studies throw any light on the life-expectancy of an intelligent civilisation?” This is part of the Drake equation of course, and the attempt to quantify the elements of that equation is a matter of some importance to the SETI community.

Larry J. Paxton’s paper in the Handbook of Space Engineering, Archaeology and Heritage, ‘Space archaeology and science fiction’, is an excellent follow-up to Armitage’s, using modified versions of the Drake equation to try and calculate the number of possible sites in our galaxy that contain fossil remnants of life, and also the number of sites that contain cultural or technological artefacts.

In his conclusion, Armitage writes:

… our questions regarding the nature of extraterrestrial life forms and civilisations might well be more rapidly answered by means of Astro-Palaeontology or Astro-Archaeology than by direct exobiology investigations of currently existing alien life forms, or in the case of extraterrestrial intelligence by classic “active” or “passive” CETI experiments.

This might sound optimistic, even to space archaeology and SETT enthusiasts, but then again we still haven’t received a result from traditional SETI or astrobiology.

The idea of enclosing a star seems incredible, but as Dyson later wrote: ‘there is nothing so big nor so crazy that one out of a million technological societies may not feel itself driven to do.’

He proposed a ‘Search for Extraterrestrial Technology’ to look for characteristic signs of such civilizations, and searches have been done – beginning (I think) with Carl Sagan and Russell Walker in 1966.

More astonishing in some ways than the stellar enclosure is the fact that planets must be torn apart to provide the raw materials for construction.

‘One can think of several feasible methods of disassembling a planet’, Dyson wrote in a 1966 paper describing one such technique, using earth as an example. Nikos Prantzos summarizes:

Dyson proposes accelerating the planet’s rotation about its axis until centrifugal forces become greater than its internal cohesive forces. At this point the object will begin to break up, projecting material into space. Breaking point is attained when the planet’s period of rotation drops to about one hour…

In order to accelerate the spin of a planet, Dyson suggests wrapping it around with an enormous metal grid into which a powerful electric current is injected. This creates an electromagnetic force which, applied in the right direction, would cause a slight acceleration in the planet’s rotation. Slowly but surely the centrifugal force would increase, particularly at the equator. When the rotation period reached breaking point, the first fragments would begin to fly off the equatorial zones of the planet. As the enormous spinning top turned faster, more and more chunks would fly off into space to be captured by a gigantic system of magnetic nets.

In Dyson’s 1966 paper, using our world as an example, he calculates that the earth’s rotation could be doubled or halted in a mere 2,500 years, and that it would take 40,000 years for the planet to begin spinning apart.

From a search for extraterrestrial technology point of view, what aspects of the planeticide process might be remotely detectable?

Off the top of my head, signatures of the disassembling process could include unusual planetary magnetospheres, rotation rates and/or oblateness, and vast quantities of spun-off matter sharing a planet’s orbit … Dyson (1966) envisions a massive array of solar energy collectors large enough to capture 300 x the solar power intercepted by the earth.

I’m not an expert in how much we can tell about exoplanets at the moment, but I think most of these are feasible or may become so. Detecting the array of solar collectors is similar to Luc Arnold’s ideas about detecting transiting astroengineering structures.

See:

Arnold, L. 2005, ‘Transit Lightcurve Signatures of Artificial Objects’, Astrophysical Journal, 627, pp. 534-539.

Dyson, F. J. 1960, ‘Search for Artificial Stellar Sources of Infrared Radiation’, Science, vol. 131, pp. 1667-8.

– 1966, ‘The Search for Extraterrestrial Technology’, in Perspectives in Modern Physics (Essays in Honor of Hans Bethe), R. E. Marshak (Editor), John Wiley & Sons, New York.

Prantzos, N. 2000, Our Cosmic Future, Cambridge University Press, Cambridge.

Sagan, C. & Walker, R. 1966, ‘The Infrared Detectability of Dyson Civilizations’, Astrophysical Journal, vol. 144, no. 3, p. 1216.

From the movie Blade Runner: an artificial snake's scales reveal clear evidence of intelligent design.

Anthropologist John Hawks has an interesting post on genomic SETI, responding to a Wall Street Journal essay by Paul Davies promoting The Eerie Silence.  

The rationale for genomic SETI is that terrestrial organisms might have been genetically modified or created from scratch by ancient extraterrestrials, and that evidence of this, even deliberate messages, might be found in their genomes.

Hawks notes the similarity to the intelligent design movement, and it reminds me of the UFO religion Raëlism, which claims that all life on Earth was created as an extraterrestrial experiment (there should be a “teach the controversy” t-shirt about that!).

Despite these associations, the idea merits serious consideration. After all, we know that many species already have been modified by human beings, either through selective breeding in the past, or genetic engineering today. These processes leave evidence – genetic and morphological. If aliens exist, they could have done the same.

Davies mentions that a number of unsuccessful searches have been made for signs of an alien message encoded in junk DNA, as far back as 1979. Hawks warns of ‘”Bible Code”-like delusion, but also considers the logistical problems of ensuring that a message could be successfully transmitted:

Consider the difficulty of transmitting a message through DNA over 10 million years. If your DNA “message” is neutral to the organism’s fitness, then the chance it will eventually be fixed in that population is its initial frequency. So, if you want a 50% chance of survival in that population, you’ve got to find and tag 50% of the individuals. Then, you’ve got to pick which populations will survive. Possibly more abundant populations will be more likely to persist, but you’ll have to tag many more individuals in those cases.

I have a copy of Davies’ book, so I can report that the theoretical method of transmitting the message doesn’t require alien visitors to round up entire populations of animals. They don’t even have to leave their home system.

Instead, an extraterrestrial civilization might consider modifying a naturally-occurring nanomachine to convey their message: viruses. Davies writes:

‘A typical virus contains thousands of bits of information encoded in either RNA or DNA – enough for a decent message. So why not engineer trillions of viruses, package them in pea-sized microprobes, and spew them around the galaxy?’

When the viruses encounter a DNA-based cell, they would be programmed to infect them, inserting their message into the germ cells of an organism. ‘Whole chunks of human DNA’, Davies reminds us, ‘are the genomic detritus of ancient viruses that infected our ancestors.’

There are a host of other logistical problems, Davies admits, such as how the aliens would know that life on Earth used DNA to encode biological information. None of the problems are insurmountable, but it got to the point where I wondered if genomic SETI advocates wouldn’t find it easier to simply assume that life on Earth originated through directed panspermia, perhaps with messages included from the beginning.

And in fact Davies does suggest directed panspermia, but for the creation of an artificial ‘shadow biosphere’ of hardy, innocuous and slow-mutating microbes that, as Hawks suggests, ’differed in some radical way from the rest of life on Earth — different genetic code, lack of common cell machinery like ribosomal RNA, etc.’

Such a population, if discovered, would be a prime place to conduct genetic archaeology.

There are two subtitles for different editions of this fine book by Paul Davies.  Subtle promotional reasons most likely dictated the variance for different markets, but ‘Renewing Our Search for Alien Intelligence’ is truer to the theme of the book. Published for the 50th anniversary of SETI, Davies, one of the best cosmological science writers of our day, uses this work to challenge the assumptions of the search for extraterrestrial intelligence.

‘How could something as bold and visionary as SETI become conservative?’ Davies asks in the first chapter. His answer: anthropocentrism (and later, what you might call ‘radiocentrism’). There’s a great sequence in the first chapter of examples of scientists basing their work on assumptions that stem from their own preoccupations, although I suppose that potential xenoarchaeologists aren’t immune to this.

As you’d expect from someone with such experience in translating profound concepts for a general audience, the book offers an accessible introduction to SETI, the history of the extraterrestrial life debate, an overview of astrobiology (including an interesting chapter on the search for a second ‘shadow biosphere’ on Earth) and the Drake Equation. Towards the end there’s an overview of how we might response to first contact (Davies is chair of the SETI Post-Detection taskgroup in the International Academy of Astronautics).

But it’s the middle of the book, from chapter 5 onward that Davies sets himself up as a SETI iconoclast:

‘The traditional approach to SETI is based on the belief that alien civilizations are targeting Earth with narrow-band radio messages. But in my opinion, this ‘central dogma’ simply isn’t credible.’

This doesn’t seem too iconoclastic to me – Davies gives an overview a number of alternate SETI programs: neutrino messaging, beacons, probes, nanoprobes, Allen Tough’s IETI program and even genetically-tailored microbe probes, all ideas which have been around for a while I think, but which are perhaps gaining some acceptance because of the ‘eerie silence’ which ‘prompts us to re-evaluate [...] and consider other ways an alien intelligence might leave identifiable traces.’

Davies sees this new paradigm as akin to forensics, but it seems archaeological to me (of course):

‘The universe is a rich and complex arena in which signs  of alien intelligence might be buried amid a welter of data from natural processes, and unearthed only after some ingenious sifting.’

The Solar System appears primordial, but Davies asks us to consider what anomalies, what remains or what absences, we might find that could point in the direction of palaeocontact. Further: what signs of alien super technology or astroengineering might we be able to detect at great distances?  These are signs that a carefully constructed SETI experiment can search for that don’t rely on a signal being deliberately targeted – they are simply the result of an alien civilization going about its routine activities.

Again, these ideas aren’t particularly new, they’ve been floating around for a while in the alternative SETI community. But it’s good to see it receiving serious and mainstream attention.

In summary, The Eerie Silence is a good introduction to SETI with a slant towards non-traditional methodology, which includes some of the main space archaeology fields.

A lot of it I’d seen elsewhere, but the book is aimed at a general audience. Still, if you have a deeper interest in SETI it’s worth reading, although you might find yourself wishing for some more detail in places.  There’s a chapter on postbiological intelligence, for example, which I was disappointed to see made no mention of Steven J. Dick except in a footnote. Dick is synonymous with that paradigm (in my mind anyway).

My prior post featured a Venn diagram illustrating the conceptual space of the field and the interrelationships of its subfields of aerospace, xeno- and exo- archaeology. Alun asks whether this definition adds anything, and whether it’s necessary to draw boundaries around the field.

Should a definition add anything or should it describe and clarify? I think the diagram adequately encapsulates the subject, even though I wasn’t sure how to visually convey the way that space heritage and exogarbology permeate the subfields (perhaps some kind of hatching?).

Is the definition limiting? Perhaps I’m wrong, but the diagram seems to encompass all possible fields that could be considered space archaeology, and I’m fairly confident that even unthought-of fields would fit into the diagram (xeno-maritime archaeology?).

Should mostly hypothetical fields such as xenoarchaeology and exoarchaeology be included? I’d argue for their inclusion on the following grounds:

1. a moderately optimistic view of the future will provide these fields with subjects to study; and
2. legitimate work (both theoretical and practical) is already being done! e.g., William Doleman’s survey of the alleged Roswell crash site, not to mention various SETA projects. A negative result is still a result.

At this point in time, I’d consider xenoarchaeology and exoarchaeology to be protosciences, so to speak. Consider this piece by Seth Shostak arguing for the legitimacy of astrobiology, another science without a subject.

Alun raises a great point that xenoarchaeological work can reveal a lot about the response of humans to perceived alien visitation. Compare it to the archaeologies of quarantine, tourism, say – even of religious sites (cargo cults?).

The study of human responses to contact is a legitimate and interesting anthropological research program, that may have an archaeological component … but I think there’s more that can be done in xenoarchaeology even now. Particularly in ‘skeptical xenoarchaeology’ of purported alien sites.

Alun writes: ‘a serious study of how xenoarchaeology is practiced could give genuinely useful insights into the assumptions in SETI programmes.’

He’s right on the nail here: more attention lately is being directed at non-traditional SETI methods (i.e. non-radio) as assumptions are challenged and SETA (search for extra-terrestrial artefacts) become more widely accepted. I’ve just read Paul Davies’ new book, The Eerie Silence, which gives a brief and telling history of the way that the cultural preoccupations of SETI scientists reflected on their visions of alien motivations.

Similarly thinking about exoarchaeology now highlights the issues and challenges that will be faced by future archaeologists, as Alun writes. Space junk is a great example here, with seemingly chaotic post-depositional factors needing to be taken into consideration.

In passing, Alun seems to think of SETI as an anthropological concern. Leaving aside the question of whether a discipline with a name derived from the Greek anthropos can encompass nonhumans, I approach SETI from the opposite direction, seeing almost all SETI as inherently archaeological.

Unless you’re very optimistic about the proximity and/or lifespan of extraterrestrial civilisations, any signal or artefact detected is likely come from a dead, or at least remotely historical culture. This isn’t only because of the tyranny of distance, but also because of what I see as a corollary of the Drake equation: that extinct civilisations will greatly outnumber extant ones.

It’s good to get feedback on these posts – thanks, Alun!

1. At the Mountains of Madness (1936), by H. P. Lovecraft
   A major work in the hugely influential horror writer’s Cthulhu Mythos, this novella about a 1930 expedition to Antarctica revolves around the discovery of an ancient, cyclopean and inhuman city. It has been argued that Lovecraft’s tales of creatures from the stars visiting earth in prehistory influenced Erich von Däniken’s ‘ancient astronaut’ theories.
2. Rogue Moon (1960), by Algis Budrys
   Another seminal work, this Hugo-nominated novel about the exploration of an utterly incomprehensible and deadly structure on the Moon illustrates the sensory and intellectual limitations of humanity in the face of forces we’re not evolved to deal with and technology far beyond our comprehension. Think of J. B. S. Haldane’s line about the universe being queerer than we can suppose (or stranger than we can imagine, in the common paraphrase).
3. Across A Billion Years (1969), by Robert Silverberg
   A fun adventure story featuring actual archaeologists exploring the remains of an ancient civilization. It’s a good example of the archaeological subgenre in which the study of alien ruins becomes a search for the surviving creators.
4. Rendezvous With Rama (1972), by Arthur C. Clarke
   A hard science fiction classic, winner of both the Hugo and Nebula awards, about a huge automated alien spacecraft passing through our solar system. The novel is archetypical of tales in which the exploration of a huge alien structure is basically the entire plot – the ‘ticking clock’ of a limited window of exploration adds some tension to the story. Don’t bother with the sequels.
5. Total Eclipse (1974), by John Brunner
   An archaeological expedition studying a civilization to determine the cause of its extinction is a fairly typical storyline. But while the novel has its flaws, the mysteries of the Draconian race are intriguing and original, and the depiction of the mission itself is vivid and detailed. Typically of Brunner and I think of 70s science fiction, there are political and economic woes on Earth that jeopardise the mission.
6. Where Time Winds Blow (1981), by Robert Holdstock
   A superb science fiction novel from the late Robert Holdstock, an author usually associated with fantasy.  Set on a somewhat surreal world where the eponymous Time Winds can carry away the unlucky, but also deposit strange and valuable artefacts, which are sought after by scavengers and scholars. This is a wonderful book which depicts the treasure-hunter subgenre of archaeo-SF.
7. Icehenge (1984), by Kim Stanley Robinson
   Robinson is a hard science fiction author best known for his Mars trilogy, and this novel about a Soviet-dominated future Mars is a good companion to those later works. The novel tells the story in three parts of the way an uprising is represented by eyewitnesses, history and archaeology. (This could be the best novel on the list!).
8. Queen of Angels (1990), by Greg Bear
   This isn’t really an archaeological novel. In fact, it’s more crime/police procedural. I’ve added it to the list, though, because of a fascinating subplot involving a space probe exploring an Earth-like planet orbiting Alpha Centauri. This is hard science fiction at its finest and most adamantine, and the robotic AXIS probe in this book is one of the best depictions of how an archaeological survey might be conducted in another stellar system (in a universe where faster-than-light travel is impossible).
9. Engines of God (1994), by Jack McDevitt
   This list wouldn’t be complete without something by Jack McDevitt. Almost all of his novels feature archaeological, historical or antiquarian plots. This is one of his better works, and the first of the Academy/Hutch series. Like Across a Billion Years, it’s an adventure yarn about archaeologists following a trail of discoveries across the galaxy, this time to discover what connects a series of vanished civilizations.
10. Wasteland of Flint (2003), by Thomas Harlan
    An alternate future where the Aztec empire rules human space, and first in Harlan’s great ‘In the Time of the Sixth Sun’ series. Starring a xenoarchaeologist, this is a fast-paced action space opera featuring ancient civilizations and immensely powerful technology.