Category Archives: The Liminal Zone

Artificial Intelligence – Thoughts and News

My science fiction books – Far from the Spaceports and Timing, plus two more titles in preparation – are heavily built around exploring relationships between people and artificial intelligences, which I call personas. So as well as a bit of news about one of our present-day AIs – Alexa – I thought I’d talk today about how I see the trajectory leading from where we are today, to personas such as Slate.

Martian Weather Alexa skill web icon
Martian Weather Alexa skill web icon

Before that, though, some news about a couple of new Alexa skills I have published recently. The first is Martian Weather, providing a summary of recent weather from Elysium Planitia, Mars, courtesy of a public NASA data feed from the Mars Insight Lander. So you can listen to reports of about a week of temperature, wind, and air pressure reports. At the moment the temperature varies through a Martian day between about -95 and -15° Celsius, so it’s not very hospitable. Martian Weather is free to enable on your Alexa device from numerous Alexa skills stores, including UK, US, CA, AU, and IN. The second is Peak District Weather, a companion to my earlier Cumbria Weather skill but – rather obviously – focusing on mountain weather conditions in England’s Peak District rather than Lake District. Find out about weather conditions that matter to walkers, climbers and cyclists. This one is (so far) only available on the UK store, but other international markets will be added in a few days.

Who remembers Clippy?

Current AI research tends to go in one of several directions. We have single-purpose devices which aim to do one thing really well, but have no pretensions outside that. They are basically algorithms rather than intelligences per se – they might be good or bad at their allotted task, but they aren’t going to do well at anything else. We have loads of these around these days – predictive text and autocorrect plugins, autopilots, weather forecasts, and so on. From a coding point of view, it is now comparatively easy to include some intelligence in your application, using modular components, and all you have to do is select some suitable training data to set the system up (actually, that little phrase “suitable training data” conceals a multitude of difficulties, but let’s not go into that today).

Boston Dynamics ‘Atlas’ (Boston Dynamics web site)

Then you get a whole bunch of robots intended to master particular physical tasks, such as car assembly or investigation of burning buildings. Some of these are pretty cute looking, some are seriously impressive in their capabilities, and some have been fashioned to look reasonably humanoid. These – especially the latter group – probably best fit people’s idea of what advanced AI ought to look like. They are also the ones closest to mankind’s long historical enthusiasm for mechanical assistants, dating back at least to Hephaestus, who had a number of automata helping him in his workshop. A contemporary equivalent is Boston Dynamics (originally a spin-off from MIT, later taken over by Google) which has designed and built a number of very impressive robots in this category, and has attracted interest from the US military, while also pursing civilian programmes.

Amazon Dot - Active
Amazon Dot – Active

Then there’s another area entirely, which aims to provide two things: a generalised intelligence rather than one targeted on a specific task, and one which does not come attached to any particular physical trappings. This is the arena of the current crop of digital assistants such as Alexa, Siri, Cortana and so on. It’s also the area that I am both interested in and involved in coding for, and provides a direct ancestry for my fictional personas. Slate and the others are, basically, the offspring – several generations removed – of these digital assistants, but with far more autonomy and general cleverness. Right now, digital assistants are tied to cloud-based sources of information to carry out speech recognition. They give the semblance of being self-contained, but actually are not. So as things stand you couldn’t take an Alexa device out to the asteroid belt and hope to have a decent conversation – there would be a minimum of about half an hour between each line of chat, while communication signals made their way back to Earth, were processed, and then returned to Ceres. So quite apart from things like Alexa needing a much better understanding of human emotions and the subtleties of language, we need a whole lot of technical innovations to do with memory and processing.

As ever, though, I am optimistic about these things. I’ve assumed that we will have personas or their equivalent within about 70 or 80 years from now – far enough away that I probably won’t get to chat with them, but my children might, and my grandchildren will. I don’t subscribe to the theory that says that advanced AIs will be inimical to humankind (in the way popularised by Skynet in the Terminator films, and picked up much more recently in the current Star Trek Discovery series). But that’s a whole big subject, and one to be tackled another day.

Meanwhile, you can enjoy my latest couple of Alexa skills and find out about the weather on Mars or England’s Peak District, while I finish some more skills that are in progress, and also continue to write about their future.

Mars Insight Lander, Artist’s impression (NASA/JPL)


Far from the Spaceports cover
Far from the Spaceports cover

In my science fiction stories, I write about artificial intelligences called personas. They are not androids, nor robots in the sense that most people recognise – they have no specialised body hardware, are not able to move around by themselves, and don’t look like imitation humans. They are basically – in today’s terminology – computers, but with a level of artificial intelligence substantially beyond what we are used to. Our current crop of virtual assistants, such as Alexa, Cortana, Siri, Bixby, and so on, are a good analogy – it’s the software running on them that matters, not the particular hardware form. They have a certain amount of built-in capability, and can also have custom talents (like Alexa skills) added on to customise them in an individual way. “My” Alexa is broadly the same as “yours”, in that both tap into the same data store for understanding language, but differs in detail because of the particular combination of extra skills you and I have enabled (in my case, there’s also a lot of trial development code installed). So there is a level of individuality, albeit at a very basic level. They are a step towards personas, but are several generations away from them.

Now, one of the main features that distinguishes personas from today’s AI software is an ability to recognise and appropriately respond to emotion – to empathise. (There’s a whole different topic to do with feeling emotion, which I’ll get back to another day). Machine understanding of emotion (often called Sentiment Analysis) is a subject of intense research at the moment, with possible applications ranging from monitoring drivers to alert about emotional states that would compromise road safety, through to medical contexts to provide early warning regarding patients who are in discomfort or pain. Perhaps more disturbingly, it is coming into use during recruitment, and to assess employees’ mood – and in both cases this could be without the subject knowing or consenting to the study. But correctly recognising emotion is a hard problem… and not just for machine learning.

From the article ‘Emotion Science Keeps Getting More Complicated. Can AI Keep Up? ‘ by Dr Rich Firth-Godbehere

Humans also often have problems recognising emotional context. Some people – by nature or training – can get pretty good at it, most people are kind of average, and some people have enormous difficulty understanding and responding to emotions – their own, often, as well as those of other people. There are certain stereotypes we have of this -the cold scientist, the bullish sportsman, the loud bore who dominates a conversation – and we probably all know people whose facility to handle emotions is at best weak. The adjacent picture is taken from an excellent article questioning whether machines will ever be able to detect and respond to emotion – is this man, at the wheel of his car, experiencing road rage, or is he pumped that the sports team he supports has just scored? It’s almost impossible to tell from a still picture.

From a human perspective, we need context – the few seconds running up to that specific image in which we can listen to the person’s words, and observe their various bodily clues to do with posture and so on. If instead of a still picture, I gave you a five second video, I suspect you could give a fairly accurate guess what the person was experiencing. Machine learning is following the same route. One article concerning modern research reads in part, “Automatic emotion recognition is a challenging task… it’s natural to simultaneously utilize audio and visual information“. Basically, the inputs to their system consist of a digitised version of the speech being heard, and four different video feeds focusing on different parts of the person’s face. All five inputs are then combined, and tuned in proprietary ways to focus on details which are sensitive to emotional content. At present, this model is said to do well with “obvious” feelings such as anger or happiness, and struggles with more weakly signalled feelings such as surprise, disgust and so on. But then, much the same is true of many people…

A schematic learning network (from

A fascinating – and unresolved – problem is whether emotions, and especially the physical signs of emotions, are universal human constants, or alternatively can only be defined in a cultural and historical context. Back in the 1970s, psychological work had concluded that emotions were shared in common across the world, but since then this has been called into question. The range of subjects used for the study was – it has been argued – been far too narrow. And when we look into past or future, the questions become more difficult and less answerable. Can we ever know whether people in, say, the Late Bronze Age experienced the same range of emotions as us? And expressed them with the same bodily features and movements? We can see that they used words like love, anger, fear, and so on, but was their inward experience the same as ours today? Personally I lean towards the camp that emotions are indeed universal, but the counter-arguments are persuasive. And if human emotions are mutable over space and time, what does that say about machine recognition of emotions, or even machine experience of emotions?

One way of exploring these issues is via games, and as I was writing this I came across a very early version of such a game. It is called The Vault, and is being prepared by Queen Mary University, London. In its current form it is hard to get the full picture, but it clearly involves a series of scenes from past, present and future. Some of the descriptive blurb reads “The Vault game is a journey into history, an immersion into the experiences and emotions of those whose lives were very different from our own. There, we discover unfamiliar feelings, uncanny characters who are like us and yet unlike.” There is a demo trailer at the above link, which looks interesting but unfinished… I tried giving a direct link to Vimeo of this, but the token appears to expire after a while and the link fails. You can still get to the video via the link above.

Meanwhile, my personas will continue to respond to – and experience – emotions, while I wait for software developments to catch up with them! And, of course, continue to develop my own Alexa skills as a kind of remote ancestor to personas.

Timing Kindle cover
Timing Kindle cover

Future life in space

Two quick bits of space news this week that – all being well – could make their way into a story one day.

Prototype of steam-propelled space probe (University of Central Florida, via

The first was an idea of powering space probes by steam. Now, at first read this sounds very retro, but it deserves some thought. In space, you can’t move along by means of steam pressure turning wheels – there is nothing against which to gain traction. Steam-propelled rockets work like any other rocket – something gets ejected at great speed in one direction, so as to accelerate the rocket in the opposite direction. The steam engine part of the probe is a means of converting the fuel supply into something that can be directed out of the thruster nozzle. The steam, heated as hot as possible to give a high nozzle exit temperature, is the propellant.

The cool thing about pushing steam out of the back, is that it comes from water, and in particular ice. And, as we have been discovering over the last few decades, water ice is extremely common throughout the solar system, and more widely through the universe. So as and when the steam-powered spaceship starts to run low on fuel, it can land on some promising object and collect some more ice. The fuel supply, while not strictly unlimited, is vastly common wherever we’re likely to go. As and when needed, solar panels or (further from the sun) a standard radioactive decay engine can give a boost, but the steam engine would do the grunt work of getting from one refueling station to the next.

Is there wine on Mars? (JPL/Caltech via

Secondly, pursuing my occasional theme of alcohol in space, I read about a firm from Georgia (the country, not the US state) that wants to develop grape varieties that would survive on Mars and, in due course, be convertible into decent wine. This would be a serious challenge, given the low air pressure, high carbon monoxide levels, and wide temperature swings of said planet. As a rough rule of thumb, the air at the Martian surface is about the same as at 20,000′ here on Earth. Apparently, white varieties are reckoned to be more adaptable than red, but I suspect that we are a little way away from resounding success here.

Other attempts to ensure that future space travellers will not have to go without booze include Budweiser sending barley seeds into space to identify the effect of microgravity on germination, steeping and kilning – three steps in the production of malt. See this link. Allegedly, also, a bottle of Scotch Whisky spent three years on the ISS before returning to Earth for analysis… the resulting taste was said to be disappointing. I hope the ISS crew got a few measures out of the bottle before sending it back down again.

That’s it for today, except to wonder again how each of these ideas could be storified. My own near-future science fiction books assume an advanced version of today’s ion drives for propelling spacecraft, but there’s no reason why steam propulsion might not appear as a previous experiment. As to wine in space, well I have already assumed that the problems of fermenting beer in microgravity have been resolved, so again this would have to be a retrospective view of historical developments. Basically, both of these innovations are set between today and my own future world. So I’m looking forward to seeing how they get sorted out in the next decade or two…

Ultima Thule

A very quick blog today, as I have been occupied all day in wood preparation (of which, more another day).

So this is to celebrate the safe passage of the New Horizons space probe past Ultima Thule, a small rock out beyond Pluto, out in the Kuiper Belt. The flyby – at some 44 kilometres per hour – happened around 5:30 am UK time on January 1st, when I suspect most of us were still in bed after the New Year’s Eve celebrations!

The journey from Earth (Johns Hopkins University)

So far all we have had back are a few low-resolution images on the final stages of approach, and a post-flyby signal confirming that the probe had survived. This survival was by no means guaranteed – nobody knew if Ultima Thule was accompanied by clouds of dust or smaller rocks, and hitting them at 44kph would have been fatal.

However, there is something like 7GB of data waiting to be sent home, all to be sent by a transmitter much less powered than the average light bulb, with each signal taking over 6 hours to get home. It’s rather extraordinary that we can pick up the data download at all, and at such a low data rate it will take the better part of two years to get the whole lot back safely.

New Horizons – until now – has been best known for the remarkable pictures of Pluto and Charon, which we enjoyed back in 2015. These have radically reshaped our views of these bodies, and vastly enriched our understanding of them. Not only that, but they inspired large parts of the setting of The Liminal Zone, which could not have existed in its present form without this additional knowledge.

Charon, from New Horizons (NASA/JPL)

So here by way of celebration is a short extract from The Liminal Zone, using geography that would have been pure guesswork before 2015.

In the approach vid, Charon was rapidly changing from a remote celestial body into a diversely coloured and textured terrain. From a bright point of light, to a disk which filled the sky. From a name, to a home, however temporary. She gazed intently at it, trying to fix the setting in her mind. The habitat was situated on the interface between the largely flat expanse of Vulcan Planum on one side, and rugged folds of hills alongside Serenity Chasma on the other. She had briefly skimmed the original surveyors’ reports; so far as she remembered, the location was a compromise between stability and ease of construction.

As yet, I have no plans to set a book out in the Kuiper Belt, but who knows what might happen when the full data set comes back?

Laws, qualifications, and the drinking of alcohol

University of Cumbria at Barrow - where I took the course
University of Cumbria at Barrow – where I took the course

I heard today that I had passed the study element of a Personal Alcohol Licence, which (after I have gone through a police background check and a few other formalities) allows me to authorise the sale of alcohol in England and Wales. Not in Scotland, Northern Ireland, or indeed anywhere else in the world, but I guess you have to start somewhere.

Now, this is far from my most advanced academic qualification, but the intriguing thing about this one is that it legally entitles me to supervise – and therefore take legal responsibility for – the public sale of what is undoubtedly a kind of drug. Without the licence, I can work under someone else’s supervision, but cannot just set up and flog booze on my own account. With it, and subject to a bunch of other constraints, I can do just that.

You can imagine that a fair proportion of the material, and the final test, focused around UK law relating to drink. There are obvious things to do with the age of the drinker, but I also learned that it is a specific legal offence to sell alcohol to someone who (in the considered opinion of the seller) is already drunk. Too much like shooting fish in a barrel, I suppose. Most of the laws fit around common sense, though as with any body of legal material you are left a little perplexed as to why specific conditions were imposed.

Russian troops and Finnish smugglers, 1853 (Vasily Hudiakov, WIki)
Russian troops and Finnish smugglers, 1853 (Vasily Hudiakov, WIki)

Anyway, all this set me thinking about law and qualification. The government of the day, however it was decided, has for a very long time indeed decided that it is entitled to a certain proportion of the profits from various kind of sales – and alcohol has typically been way up the list. And of course where rulers try to enforce a ruler, some subjects will concoct cunning schemes to get around the additional expense – excise duty spawns groups of smugglers almost by definition. But you only risk smuggling goods where the financial equation makes sense – small, easily concealed items where the tax duty is high enough that you can pocket a decent cut for yourself, while still leaving the buyer feeling they have done very well out of the deal.

So customs duties, and the body of regulations which underpin them, have been around for millennia. And – typically – part of those regulations consists of ways to appoint specific individuals as those few who are allowed to make transactions. In days of old, one suspects that many of these appointments were based on nepotism or bribery… if you had the right connections, or could stump up enough starting cash, you could find yourself in a comfortable position and set up for life. Nowadays the process is rather more transparent, and the barriers to entry are very much lower.

The Jolly Sailor, Bursledon (
The Jolly Sailor, Bursledon (

But equally, things have been tightened up in other ways. A couple of hundred years ago, it was fairly common for ex servicemen to use their prize money, or sign-off pay, or whatever they had saved up, to buy a little inn somewhere, and make a tidy living brewing or distilling booze of widely varying quality, and plying locals with the results. (Any pub you find called the Marquis of Granby recalls charitable donations by this 18th century gentleman who donated money to wounded servicemen). Provided you could afford a small building and a few bits and pieces to do the fermentation, you could set yourself up, no questions asked. These days, you have to go through hoops like planning permission, health and safety, police, plus of course getting a premises licence. There are all kinds of reasons why an apparently sound business plan might be rejected by officialdom.


So that is looking back… but what about forwards? Right now the only human outpost we have away from the Earth is the ISS. It’s not very far away – about 400km above the surface of the Earth, less than the distance from one end of England to the other. And I don’t suppose that the occupants have much privacy or opportunity to set up fermentation or a distillery up there. Though I did hear today that Budweiser has funded one of the science experiments on board, seeking to improve strains of barley with increased resistance to environmental stress. So maybe next year someone wil fund a experiment to make beer up there and see how yeasts behave in microgravity!

Alexa Far from the Spaceports logo
Alexa Far from the Spaceports logo

But let’s assume that within the next couple of decades we have an outpost or two somewhere else – the Moon, say, or Mars, or even a privately operated space station. How likely is it that nobody will attempt to ferment fruit or vegetable juices? And whose laws will be applied to regulate such an operation? Now run the scenario on a few more years, into the solar system I imagine for Far from the Spaceports and its sequels. There are a decent number of scattered habitats, each separated from the others by at least days, often weeks, and sometimes months of travel time. It will, I suspect, become impossible to try to enforce some kind of uniform system of laws.

Alexa Timing logo
Alexa Timing logo

My guess is that each habitat will have its own local set of laws and customs – no doubt broadly consistent with each other, but differing in detail. Sure, you can send a message anywhere in the solar system within a day at most, but if you get a tip-off that the habitat on Charon is bootlegging some kind of moonshine drink that is not allowed on the Moon, it’s going to take your police three or four months to trek out there and investigate. Will they bother? In that kind of situation, I don’t think it is feasible to try to maintain a single unified system of laws and regulations. So now suppose I have trained for my personal alcohol licence here on Earth (which in fact I did), and then decide on a whim to travel out to Charon. Will a publican out there recognise my licence? Or will he or she make me study for a duplicate one, ending up with a signature of someone on Charon rather than Earth? Right now, in the present day, it is extraordinarily hard to transfer qualifications between countries in professions like teaching, nursing, psychotherapy, and so on – will things be any different when we’re scattered across a few dozen habitats? I suspect not, especially as my own new licence doesn’t even allow me to do stuff in Scotland!

All of which is why I like writing about that near-future band of time, when there is no Federation, no Galactic Empire, or whatever – only local enforcement of issues according to moral and social principles which makes sense to the occupants. I suspect the chief coordinating factor would be economic – if you felt that some particular habitat was doing things the wrong way, you wouldn’t trade with them. They would become isolated, and there’s nowhere in the solar system away from Earth that can actually be self-sufficient. Hence I write about economic and financial crime, as these are the things that seriously threaten lives and livelihoods.

Dawn, death, and ion drives

Dawn takes off, September 27th 2007 (KSC/NASA)
Dawn takes off, September 27th 2007 (KSC/NASA)

Last week, NASA’s Dawn space probe, which first launched back in 2007, finally ran out of fuel and has been declared dead. Regular readers will know that Dawn has been a great source of information and inspiration for me as I have been creating the future world of Far from the Spaceports, Timing, and the in-progress The Liminal Zone. So it seemed fitting to me to do a kind of tribute to Dawn here.

So here’s a timeline of key events:

  • September 2007 — Launch
  • February 2009 — Mars Gravity Assist
  • July 2011 — Vesta Arrival
  • September 2012 — Vesta Departure
  • March 2015 — Ceres Arrival
  • June 2016 — End of prime mission
  • July 2016 — Start of first extension
  • November 2017 — Start of second extension
  • November 2018 — No remaining fuel: mission ends

Enhanced colour image of Ceres (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
Enhanced colour image of Ceres (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

Of course, Dawn is not going anywhere – it will remain in its current orbit around Ceres for decades at least, until some combination of inevitable gravitational perturbations distorts that orbit enough that it eventually crashes into the surface. But there will be no more navigation from Dawn, no more course correction, no more photos or science information.

I want to talk a bit about Dawn’s ion drive, in the connection of storytelling, but if you want pictures and information about the mission findings, the best place to start is the NASA site, which has separate pages for Vesta and Ceres.

So, the ion drive. Most craft up to now have used chemical rockets – two or more chemicals are stored separately, then mixed to form a high-energy burst of propulsion. For example, the latest SpaceX SuperDraco engine uses the two liquids nitrogen tetroxide and Monomethylhydrazine. The net effect is that the spacecraft is pushed with high acceleration in a particular direction. After this engine burn, the craft coasts with no further propulsion for days or months, until it’s time for another correction. Astronauts in the craft have to endure short periods of high g-forces, followed by long periods of weightlessness. The engine burns have to be very precisely calculated for direction, force, and duration, so as to minimise the need for subsequent burns. Once the fuel is gone, it’s gone, and each burn takes a fair proportion of the fuel stores.

Falcon Heavy launch, February 6th 2018 (SpaceX via Wikipedia)
Falcon Heavy launch, February 6th 2018 (SpaceX via Wikipedia)

What does this mean for storytelling? Well, most of the journey is spent at zero acceleration, coasting towards your destination without burning fuel, and without any sense of up or down. It took the Apollo astronauts about three days to get from the Earth to the Moon (and the same back again, after doing stuff on the lunar surface). As and when SpaceX or whoever sends another rocket there, it will still take about three days – the time taken is a result of the coasting period without power, not the force of the engine. And because of the long zero-gravity sections, you need to be fairly well-trained to manage this.

SpaceX 'Starman' orbit (SpaceX Twitter feed)
SpaceX ‘Starman’ orbit (SpaceX Twitter feed)

Now consider a trip to Mars. In February of this year, SpaceX launched a Falcon Heavy rocket, with payload of a Tesla car and suitable contents. It left Earth orbit and headed out on an orbit that goes out past Mars, but at a slight angle so that the two never intersect. Each orbit takes 557 days to complete, so at this point not even one has been finished. The payload – a Tesla car – passed by Mars orbit a few days ago, after about eight months.

The Hermes rocket from the film The Martian (
The Hermes rocket from the film The Martian (

Now, this rocket had not reserved enough fuel to slow down and enter Mars orbit – it was a vivid proof of concept for SpaceX, not a real attempt to land on the Red Planet. But basically, if a human crew does the same journey in the same rocket, it will take them about eight months to get there – eight months of zero gravity, unless rocket design changes to include a kind of pseudo-gravity produced by rotation, as in the Hermes spacecraft in The Martian.

Getting out into the solar system on chemical rockets just prolongs these figures. Potential astronauts have to cope with months, if not years, of isolation and low gravity. It is just not viable to send people there, which is why the present focus has been on sending hardware and instruments.

Schematic diagram of ion drive (NASA/JPL)
Schematic diagram of ion drive (NASA/JPL)

Enter the ion drive, as used on Dawn and a handful of other craft. It is, in some ways, the opposite of a chemical rocket. It produces small amounts of drive thrust continuously for a very long time. NASA estimates that the thrust of the engines on Dawn is roughly the same as what you feel when you hold a piece of paper on the palm of your hand. It’s quite useless for getting off the Earth’s surface – you really do need something powerful for that – but as a way to get you from Earth to Vesta… or Vesta to Ceres… From a standing start in free space, Dawn would take about four days to go from 0 to 60 mph. But that ion drive just keeps piling on speed. Dawn’s engine ran for a total of about 2000 days during the mission – over 5 years.

Artist's impression, Dawn at Ceres (NASA/JPL)
Artist’s impression, Dawn at Ceres (NASA/JPL)

Now, if you have an engine that is always-on, your whole picture of the solar system changes. Let’s suppose you keep accelerating to the mid point, then flip over and decelerate the rest of the way, so that you get to feel a constant gravity all the way. Then further is more efficient. In twice the time you can go four times the distance. Or, to put the same thing another way, to go twice the distance takes less than one and a half times the time.

Of course, Dawn’s motors were still early versions of the design, with a low thrust output even at maximum. For my stories, I’ve assumed that the design can be enhanced to give an acceleration equivalent to 1/20 of that at Earth’s surface – considerably less than what you get on the moon. It would take some getting used to, but it means that your body and brain have a clear sense of up and down, and all those physiological functions that need gravity have a good chance to keep going! What does this mean for travel time?

  • Earth to Mars takes between ten and twenty days, depending on their relative position at the time of launch
  • Earth to Ceres takes about 3 weeks
  • Earth to Pluto takes about three months

Timing Kindle cover
Timing Kindle cover

That works for storytelling – it’s not very different from journeys that people would take by sail back in the day. For example, an 18th century trip from England to India would take something like four to six months. Once the Suez canal was open, this reduced to about two months. People will put up with a journey like that for all kinds of reasons. So that’s roughly how you can imagine the solar system of my science fiction novels – a bit like our world was in the days of sail and early steam ships.

Here’s a short extract from Timing, in which journey time gets discussed a bit. Meanwhile, RIP Dawn!

Then, quite suddenly, I had been sent all the way to the Jovian system. That would have been fair enough after the local jobs, but it turned out to be a false alarm. One of the analysts thought he had seen a recurrence of an old scam, running out of the Callisto hub. So off we had gone – a long journey for both Slate and I, and when we left Earth orbit the planetary alignment meant there were no friendly stopovers to break the journey.

Once we got there, the two of us had poked around, wormed our way into this module and that, but found nothing. To be sure, we confirmed that the reported irregularities were real. We had easily managed to find the batch runs where the credit had gone missing, by comparing input and output. It happened every time a specific input value was missing or unreadable, and a default value had to be assumed. But the chosen default looked right and we couldn’t find root cause. The code was non-standard, and frustratingly weird, but there was nothing obviously suspicious. The logs were so skimpy as to be almost useless. It did not seem to be the kind of task that needed our skills, nor to be as much of a problem as the analyst had first thought.

When it was over, and having drawn a blank, we sent a summary report down to the Finsbury Circus office, suggesting that perhaps it would be more effective to send an accountant. We had managed to get four weeks out of the work, but it still felt like a long drag for not much return. To be fair, it was unusual for the analysts to make a mistake like that, so I was professionally polite rather than curt. Then it was time to warm up the engines of our sloop, the Harbour Porpoise, and off we set on the homeward leg.

I was all set for a boring journey back down the gravity hill to Earth, but Slate found an orbital option which would take us right past the Scilly Isles. That settled it. We deserved a reward for our fruitless diligence. So we changed the navigation plan, sent some messages ahead, and here we were. Elias, my manager back in London, had made a token protest at the diversion, but I told him that the Harbour Porpoise needed servicing and the delay was unavoidable.

Anyway, a couple of hours signal lag meant that we were already en route by the time his answer came back. We just said that we didn’t have enough reaction mass for such a radical course change. It might even have been true, though I was careful not to ask Slate for a technical analysis, and she was just as careful not to offer one.

Regardless of that, we weren’t minded to listen. Slate and I both reckoned that we deserved the break. Six weeks of voyage out to Callisto, and four weeks of fairly dull work had not made us receptive to a tedious trip straight back home again. It would mean nearly three months’ travel time for just one month of work, and we weren’t about to just put up with that without an argument.

Tesla Starman (SpaceX Twitter feed)
Tesla Starman (SpaceX Twitter feed)

Ultima Thule

Today’s blog is focused on the next target of the New Horizons probe, which back in July 2015 sent back such remarkable pictures of Pluto and Charon. But before that, here’s a quick reminder of this week’s Kindle Countdown deals for Far from the Spaceports and Timing – £0.99 / $0.99 for the next couple of days. Follow these links…

New Horizons route, including Pluto and Ultima Thule (Wiki)
New Horizons route, including Pluto and Ultima Thule (Wiki)

Right. New Horizons. After the Pluto flyby, the natural question was, what next? There was enough fuel and energy reserves to consider a small course change… but to what end? Pluto is at the inside edge of the Kuiper Belt, a tenuous and very sparsely populated volume of space. Over the last few years, we have been steadily gaining information about some of the contents, many of which have hugely elongated orbits. The big prize out there is the possibility of a really sizeable planet, acting as a gravitational shepherd to coax the smaller bodies into resonant patterns.

Planet 9 has not yet been found, but several smaller bodies have. And one of them, catalogue number KBO 2014 MU69 , happened to be well placed for New Horizons. So, an appropriate course change was made as Pluto dwindled into the distance, and KBO 2014 MU69 – now provisionally renamed Ultima Thule – became the next goal.

Current New Horizons view of Ultima Thule (NASA/JHUAPL/SwRI)
Current New Horizons view of Ultima Thule (small dot on right-hand frame) (NASA/JHUAPL/SwRI)

But distances out in the Kuiper Belt are large, so there has been a considerable wait. Ultima Thule is about 12% further away from Earth as Pluto is. The actual flyby will occur on January 1st next year, and at this stage we still don’t really know what to expect. The Hubble telescope orbiting Earth shows Ultima Thule as just a slowly moving point of light. New Horizons is about 33 million miles away from it – about 1/3 the Earth-Sun distance – and still can’t resolve it to more than just a point source. We cannot make out any surface detail. We don’t know if it’s roughly spherical, or irregular, or even a little cluster of fragments all moving together. Just about all we know is that it’s less than 40 km across, and although very dark by the standards we are used to in the inner system, is slightly more reflective than expected.

Artist's impression, New Horizons and Ultima Thule (Steve Gribben/NASA/JHUAPL/SwRI)
Artist’s impression, New Horizons and Ultima Thule (Steve Gribben/NASA/JHUAPL/SwRI)

After sending the Pluto and Charon data home, New Horizons went to sleep for a couple of years, with a wake-up call in June for some of the instruments and a course correction. It is now being prepared as best we can for the encounter. It’s a fascinating problem – light or radio signals take around 6 hours to cross the gulf between us and the probe, so there is no possibility of direct control.  Any reply takes another 6 hours to get back. The systems have to be set up in advance, according to our best guess of what will be there. The final course changes will occur in mid December, when the ground crew wil decide just how close to steer towards Ultima Thule. In one sense, the nearer the better… but the higher the risk that the probe will make brief, catastrophic contact with some fragment of rock and ice. On the day, the probe will whistle by at over 30000 km/h, so there’s no opportunity for second chances. Whatever sequence has been set up in advance, will be played out without modifications. After that, New Horizons will spend the better part of two years streaming the data back to Earth. So although the rendezvous will be a New Year treat, we shall have to wait a long time until we get any high-resolution images or other data.

As yet I haven’t written about what life might be like in a suitably protected environment out in the Kuiper Belt… maybe this encounter will be the seed of another book, in the way that the flyby past Pluto and Charon has contributed to The Liminal Zone. And here, just for a bit of fun, are someone’s first impressions of the settlement on Charon, extracted from the early sections of The Liminal Zone

Nina walked steadily along the winding curves of Lethe towards Asphodel. The house AI had finally told her where Lance’s quarters were situated in Acheron, and had transferred directions onto a hand-held to direct her there. From space, the overall shape of the Charon settlement had been clear – five sinuous linear habitats, following curves in the underlying terrain and joined radially to Asphodel. When you were actually down here, it wasn’t nearly so neatly divided. There were extra little corridors and alcoves which broke up the superficial symmetry, and little tunnels that dived underground and then resurfaced at unexpected places. She was glad that the little hand-held router buzzed faintly at junctions to tell her which way to turn.

Weather – away from Earth

Last week I talked about weather on Earth, both in fact and fiction. This week, suitably enough, it’s time to think about the other planets in our solar system. And there’s plenty to talk about.

Dust storm front, northern latitudes of Mars (ESA Mars Express)
Dust storm front, northern latitudes of Mars (ESA Mars Express)

The obvious first place to start is Mars – the atmosphere is thin there (ground level on Mars is about the same as 30 km altitude here, high above the Himalayan peaks), but it’s well able to have weather patterns. There are seasonal changes, with the polar ice caps (frozen CO2, or dry ice, rather than water ice) growing and shrinking as the planet tilts one pole or the other towards the sun. Then there are erratic changes, such as dust storms which can build up over a substantial area. The Martian opened with one such storm, and the book version had a second which threatened Mark Watney’s journey towards rescue (the film skipped over this one). In the real world, back in the summer, one such storm of vast proportions cut off communication between NASA’s Opportunity rover and mission control. The problem here is not actually caused by fierce winds buffering the craft, but that the dust has blocked its ability to capture sunlight and so generate electricity (the exact problem Watney faced late on in The Martian).

Storm on Saturn seen by Cassini probe, 2010 (NASA)
Storm on Saturn seen by Cassini probe, 2010 (NASA)

Venus has ferociously fierce winds, and if ever we try to build a permanent settlement on the surface there (which personally I doubt, since orbital or high atmospheric bases would probably suffice) then they will need immensely strong anchors, and extraordinary resistance to high levels of heat and acidity. There are outline plans at present for building a lander able to survive for a few months, rather than the few hours which is all that has been achieved to date. Jupiter and Saturn have no discernible surface – probably one exists, but the pressure would be intolerable well before you reached it. They also have huge storms spreading thousands of miles across.

Artist's impression, dust storm on Titan (PGP/Labex UnivEarthS/University Paris Diderot – C. Epitalon & S. Rodriguez)
Artist’s impression, dust storm on Titan (PGP/Labex UnivEarthS/University Paris Diderot – C. Epitalon & S. Rodriguez)

But several of the moons of the giant planets are more promising. Recently, dust storms were spotted on Saturn’s moon Titan… not sand as might be on Earth or Mars, but great clouds of organic hydrocarbon molecules are stirred up into its atmosphere. So there’s definitely weather on Titan, and pretty much everywhere else we look.

Moons like Titan have been known to have atmospheres for some time, but as well as this, our solar system contains a lot of small bodies which used to be thought of as entirely airless. Closer investigation has shown that many of these actually have very thin layers of air around them. In some cases these are probably generated by underground deposits of liquid and gas which slowly ooze to the surface and evaporate. In others, we don’t yet know how they came into being. But these discoveries are reshaping how we think of our sibling worlds, and by extension the worlds we are spotting around other stars.

New Horizons image of clouds on Pluto (NASA/JPL)
New Horizons image of clouds on Pluto (NASA/JPL)

Back in 1950, EE (Doc) Smith, in First Lensman, could describe Pluto as being rocky and entirely barren. We couldn’t say that any more, not after the New Horizons probe sent back this fantastic image of air and clouds above Pluto. In Liminal Zone, my protagonists on Pluto’s moon Charon witness such changes both outside the dome where they live, and also when they look up at Pluto. Weather, it seems, is pretty universal, and will go on forming a topic of conversation for a lot of years to come.

And in a final stop-press, the existence of a new dwarf planet has just been announced. The finders were actually looking for the enigmatic Planet Nine, whose existence is suspected from a variety of gravitational anomalies in the orbits of other far-out objects. That has still not been detected, but instead they found 2015 TG387, dubbed The Goblin for simplicity. This newly recognised member of our solar system has a fantastically elongated orbit. At closest approach it is still well outside the orbit of Pluto, and at aphelion it strays 35 times as far away. It takes around 40,000 years to complete an orbit: last time it was in its present position we were sharing much of the planet with Neanderthals.

Orbit of 2015 TG387 (Roberto Molar Candanosa and Scott Sheppard, courtesy of Carnegie Institution for Science)
Orbit of 2015 TG387 (Roberto Molar Candanosa and Scott Sheppard, courtesy of Carnegie Institution for Science)

Red dwarf stars, and life away from Earth

After a few weeks in which I have been thinking about ancient Cumbria, this week I’m back in space again. In particular, this post looks at some possible locations for alien life which, until recently, were considered most unlikely. Over the last few years, thousands of planets have been identified by equipment both on Earth’s surface and in orbit. We now know that planets are exceedingly common in the galaxy, and that on average, each star has more than one planet. There are more planets near us than stars. Many of these are large in size, gas giants like our own Jupiter and Saturn – larger planets are obviously easier to detect than smaller ones – but a great many are small and rocky, more like Earth.

Artist's impression - the seven planets of TRAPPIST-1 (ESO)
Artist’s impression – the seven planets of TRAPPIST-1 (ESO)

The most extreme case we know of is designated TRAPPIST-1 (the acronym originating from the Chilean telescope which first detected them). This has seven planets, so the system is broadly like our own. And a very recent analysis suggests that each of them has liquid water at its surface, and in some cases considerably more water than we enjoy here. If we were to travel the forty light years to get there, we might well find a world which is entirely ocean.

But as well as the striking nature of the planetary system, the sun itself is interesting. Up until fairly recently, the search for life elsewhere was focused on stars which were as similar to our sun as possible. It was assumed that this was necessary in order for the associated planets would be like Earth. But TRAPPIST-1 is not at all like our sun – it is a comparatively cool red dwarf star. Red dwarfs are extremely common in space, but they are small and dim, and until modern orbital telescopes revealed the true situation, were thought to be rare.

Comparison of solar system sizes (ESO)
Comparison of solar system sizes (ESO)

Now, red dwarf stars are much cooler than our sun, between 1/3 and 2/3 of the effective temperature, so for a planet to be in the Goldilocks Zone – neither too hot nor too cold – it must be much closer to its sun. But that’s OK – in the TRAPPIST-1 system, all seven planets orbit well within the distance that super-hot Mercury circles our sun. Indeed, that system is not much larger than that of the moons of Jupiter. Red dwarfs are miserly with their energy, so you have to huddle in close to the fire to get any warmth. But along with that, they burn at their low rate for a hugely longer time than our sun will last. The hotter and brighter the star, the less time it shines for. Too short a stellar lifetime, and their might not be time for life to develop on whatever planets are around. Red dwarfs give their planets massive amounts of time to develop.

Right now we have absolutely no idea whether any of the TRAPPIST-1 planets supports life – or indeed any of the myriad other red dwarfs and their planets in our quadrant of the galaxy. But if you were a betting person, you’d be more likely to bet on life arising around a red dwarf than a super-hot star like Sirius.

Artist's impression, Ross-128b (ESO)
Artist’s impression, Ross-128b (ESO)

Now, 40 light years is inconveniently far away from Earth for exploration in reality or fiction. Our current generation of telescopes can find out a decent amount of information about the 7 planets of circling TRAPPIST-1, but not nearly as much as one would like. And if you consider near-future science fiction, without warp drives, wormholes, or other exotic ways to travel around space -as I do – then 40 light years is well beyond a realistic journey time. Happily, there are other red dwarfs much closer to us. One of these, which has been studied with great excitement for a few years now, is called Ross 128 (the rather boring name coming from a catalogue number). It has at least one planet (Ross 128-b) which appears to be a little larger and more massive than our Earth, and some calculations suggest that its surface temperature may well be around 21C. Ross 128 is only about 11 light years from Earth, so is getting towards the we-might-send-something-there territory.

I thought about using Ross 128 as the focus of interest in my in-progress novel The Liminal Zone, but in the end pitched for the even-closer Gliese 411 – another catalogue name, which for fictional purposes has been rebranded something more interesting. Gliese 411 is under 9 light years away, and is the 4th-closest star system to us. The planet Gliese 411b is, so far as we can tell, larger than Earth, and almost certainly rather hotter, but (probably) not so hot as to preclude interesting things there. And its proximity to us makes it a credible target for the Breakthrough Starshot project, in which tiny “spacecraft” with roughly the capability of a mobile phone are boosted towards their target by a laser beam shining against a light-catching sail. The miniature spaceships are called Sprites, and last year were tested for their ability to communicate from space after being launched from Earth. Each is just a few centimetres square, weighs just 4 grams, and costs a few tens of dollars. The entire actual cost of the mission is in the devices needed to boost these Sprites to their final speed.

Starshot’s current plans are for Proxima Centauri as target – the nearest star to us, a little over 4 light years away – and a boost to 1/5 light speed. Proxima Centauri is in fact another red dwarf star, and a very recent theoretical study suggests its planet may have a large ocean and survivable temperatures… though so far we lack real observations which might confirm or refute this, and other studies have suggested that the radiation levels are uncomfortably high for life to thrive.

My fictional version is a little more ambitious – Gliese 411 and 1/2 light speed. A journey time of about 17 years, plus the time taken for the homeward bound signal on arrival, means about a 25 year lag from lift-off to analysis of results. It’s still a long time, but less so than some space projects – it is now over 41 years since the two Voyager spacecraft left Earth, and we are still following them. A very recent theoretical study

As to what happens in The Liminal Zone once these little ships get there – well, it’s still work in progress, but hopefully you’ll get a chance to see for yourself early next year!

The Liminal Zone (temporary cover)
The Liminal Zone (temporary cover)


With The Liminal Zone foremost in my writing mind just now, I’m always eager to read space news about Pluto. And just recently another paper has been published analysing the surface features as revealed by the New Horizons flyby back in July 2015.

Audiobook cover
Audiobook cover

But before that, a quick reminder of the giveaway competition currently running for the audio version of Half Sick of Shadows. There were 5 copies each on Audible UK and US available free. Just follow this link, listen to the sample snippet, and get back to me with the answer. Some copies have already gone but others remain to be won! It’s absolutely free – if you don’t currently have Audible membership then you can sign up for a trial month at no cost, then cancel if you don’t like it.

Back to Pluto. The specific surface feature that the report found was dunes. Not, of course, sand dunes, but ones made of ice granules, moved about very slowly by the extremely light winds which stir the extremely thin atmosphere there. It’s a remarkable tribute to the way physical phenomena tend to mirror each other. The conditions on Earth and Pluto are radically different in ever so many ways, yet they share the ability for dunes to form on their surfaces. Like everything on Pluto, it all takes place on an immensely slow timescale – I doubt that these dunes move appreciably over a human lifetime. But nevertheless, there they are, adding to the richness and complexity of the surface features of a world which, not so long ago, was assumed to be utterly boring.

Cover - Dune (Goodreads)
Cover – Dune (Goodreads)

A science fiction reader’s first reflex, on hearing of dunes, is naturally to jump to Frank Herbert’s Dune. That world was bakingly hot, dry, and life was absolutely dominated by the survival need for water. The dunes there – sand dunes – covered the vast majority of the desert world’s surface, and concealed both exotic wildlife and a radical human culture. It seems unlikely that much life frequents Pluto, with a surface temperature around -230° Centigrade. But these days, it would be a brave person who would say it’s impossible. And The Liminal Zone is – among other things – about the human settlement on the margins of our solar system.

Finally – and since my main enthusiasm is not so much for Pluto as for its largest moon Charon, here is a video put together by NASA from the New Horizons flyby. It’s partly for fun, and partly because next week – June 22nd – is the 40th anniversary of the discovery of Charon! It’s only short, but quite cool.

After enjoying that, don’t forget the giveaway for Half Sick of Shadows!