Proxima (15 page)

And so Martha had died, stoically enough, adding another grave to the small plot they had started.

The funeral, such as it was, had been odd. Nobody here seemed particularly religious, or if they were they had kept quiet about it when the time came to speak over Martha’s body.

The ColU had surprised everybody by rolling forward. ‘She was one of us. Now she gives her Earthborn body to the soil of this new world. She will live on, in the green life to come, under
the light of another star . . .’

John had shot it a look of venomous hatred.

Since then John’s mood swung daily, from manic hilarity to over-familiarity to sullen silence to spiky aggression. They had all tried to find ways of coping with him. But they had all
shrunk back from him, Yuri thought.

Only five left
: Yuri, Mardina, John, Abbey, Matt. You couldn’t even maintain the illusion that this was somehow the seed of a colony, a city of the future, a new world. They were
castaways in this place, and after a life of toil, short or long, they were all going to die here, and that was that. The name Mardina had impulsively given to the place seemed ever more fitting.
Through adversity, to the grave. John had a right to be difficult. Why the hell not? Effectively, they were all dead already.

Yuri packed up the last of the gear, and the haul of laver, and headed for camp.

T
wenty-four hours later the ColU approached Yuri, almost shyly, and asked him to accompany it to one of its test sites to the north.

Though no native life forms had posed a threat so far, they had a rule that nobody left the camp alone, and certainly not the ColU, for they couldn’t afford to lose it. Yuri had some
transit sightings to make anyhow. So he pulled on his walking boots, got together a pack of water and dried food, and set off alongside the robot, following the Forest Road to the north.

As they left the little settlement they passed the ColU’s fields, where the robot was manufacturing terrestrial-type soil. A
robot
, a supreme artefact of a high-tech star-spanning
civilisation, making something as humble as
soil
– it had seemed like a joke to Yuri when he’d first heard about this, but he’d come to understand it was a minor biotech
miracle, and essential for their survival here on Per Ardua.

No plant from Earth could flourish in native Arduan dirt. Given enough time, lichen from Earth would break down bare rock to make usable soil, but the colonists didn’t have that much time.
So the ColU took in that Arduan dirt, and baked it and treated it chemically to adjust its levels of iron, chloride and sulphide salts. Then it seeded the dirt with a suite of terrestrial bugs:
sulphur-reducing bacteria, then cyanobacteria to fix carbon from carbon dioxide, and nitrogen fixers to process the atmospheric gas into ammonia and various nitrates usable for life. The
colony’s own waste was fed in, together with compost-starter bacteria to get it to decompose. In the end the ColU even built up the complex structure of the soil, layer by layer, with fine
manipulators on the end of its mechanical arms. The colonists joked about how it was coaxing earthworms into the new ground.

Of course the Arduan dirt was actually ‘soil’ already: native soil, supporting native life forms. These were of no use to the colonisation project. They couldn’t even be eaten.
The native creatures were eradicated, or broken down into basic nutrients to support the suite from Earth.

The first soil beds were already bearing a crop, gen-enged potatoes, their leaves stained black by their adjusted Prox-friendly photosynthetic chemistry. The spindly roots were nutritious enough
but they tasted odd to Yuri, faintly acidic maybe, and with a powdery texture. Potatoes, which after all had originated in the Andes, were a useful crop, robust enough to grow at altitude, or in
the cold and damp. You could produce several harvests a year. And potatoes, it seemed, provided all nutrients essential for a human diet except vitamins A and D, and the seaweed helped with that.
But the ColU was experimenting with other Earth crops, some gen-enged, that might be suited to the conditions. Strawberries, that required less light to flower than some plant species, and so were
preadapted for Proxima’s feebler daylight. Wheat, flexible crops like soya beans, sweet potatoes, ready-to-eat salad crops like lettuce and spinach.

The ColU told Yuri, and anybody who would listen, that they really were pioneers in a new way of living, here on Per Ardua. On Earth, humans lived in a kind of sea of other organisms, including
the bacteria that lived inside and outside their own bodies. Even in a dome on Mars you were living in a kind of closed sample of that wider sea, a droplet. Here, they were trying to recreate that
sea of Earth life in an open environment, on an alien world. It scared Yuri to hear that nobody really knew how much of that bacterial sea you actually needed, in the long term, to survive.

And it pissed off everybody else to hear the ColU, and sometimes Mardina, speak of long-abandoned plans for further flights to bring animals out here, perhaps in iron wombs.

It was all marvellous – but somehow fantastically dull at the same time. It was only, after all, soil. The fact that they all seemed doomed to be dead and gone in a few decades, no matter
how ingenious the ColU was, made it seem even more futile. Sometimes Yuri felt sorry for the ColU, which wanted to talk about its achievements and discoveries, but there was usually nobody who
wanted to listen.

Now, for example, as they walked, the ColU essayed a conversation. ‘You are preparing to make astronomy observations, Yuri Eden.’

‘Transits, yes.’

‘Transits.’ With a whir, it lifted its camera eyes, entirely contained within its bubble-dome ‘head’, to the washed-out blue sky. ‘There is the Pearl, of
course.’ The Pearl was the name they had given to Proxima e, the big super-Earth, the only planet visible in the sky of unending day. ‘Per Ardua is one of a family of six worlds. But
aside from the Pearl, the only way we can see the other planets is by transits, when the inner worlds pass across the face of Proxima itself and cast a shadow . . . Six planets in all, and six of
you left. I did wonder if you would think that was some kind of omen.’

Yuri looked at it curiously. ‘No. Anyhow, there’s only five of us now.’

‘Six if you include the ghost of Dexter Cole.’

The idea of the colony being haunted by the ghost of Dexter Cole, the first, lost, man to have been sent to Per Ardua, was a kind of black in-joke that had grown up among them. Yuri wasn’t
surprised that the ColU had overheard, but he was surprised it referred to that kind of stuff. ‘Do you think that way? Omens and stuff? Ghost stories? You’re a machine. A creature of
logic.’

‘We are all creatures of logic, at root. Of little switches turning on and off in our heads, metaphorically speaking. I do not think like a human, but I am endlessly curious
about
humans, and their ways of thought.’

‘Why? I mean, why did they program you to be curious?’

‘I need to understand you better, in order to serve you better. I am your doctor, your guide, your children’s teacher one day. It is my duty to be curious about you. Just as it is my
duty to be curious about the life forms of this world.’

‘As we scrape them off to make room for potato fields.’

It laughed, a tinny, not unattractive, but quite unrealistic sound. ‘The native life is useful.
And it is related to us
.’ It said this gravely, as if making a grand
announcement.

‘I don’t understand.’

‘It is what I have deduced myself,’ the ColU said with something like pride. ‘This was a significant achievement in itself. I do have a sophisticated genetic microlab on board,
but when we began I didn’t even know what chemical basis any genetic material here might have. In the brief time we have been here I have managed to progress from that fundamental
investigation to, by analogy, the discovery of the double helix . . . Yuri Eden, all Per Ardua life, like Earth life – that is, all I have sampled – belongs to a common family tree. And
that family is related to the family of Earth life, as if they are two mighty trunks sharing the same root. But that commonality is deep, deep in time . . .’

Yuri, trudging in the hot light, said nothing. The ColU took that as an invitation to keep talking.

‘Life on both Per Ardua and Earth is based on fundamentally the same chemistry: carbon, hydrogen, oxygen, nitrogen. Perhaps that was inevitable, given the physical nature of worlds like
these, rocky, watery worlds, rich in carbon. But the choices made in how life evolves are not inevitable. All life on Earth is based on two chemicals, two acids: DNA, which stores the information
that defines a life form, and RNA, which interprets that information and uses it to assemble proteins, which are the building blocks of life.’

‘DNA as software, proteins as hardware.’

‘That is an antiquated reference. You are showing your age, Yuri Eden. Both DNA and RNA are based on a particular kind of sugar, called ribose. Life on Per Ardua has a similar basic
architecture. The information store is not DNA – but it is a kind of acid,
based on the same sugar choice as DNA
, ribose. There were other plausible possibilities – dextrose,
for instance.

‘Beyond that fundamental point, the two methodologies of life differ. Arduan genes do not use DNA; they use that ribose-based acid, which in turn encodes information using sequences of
bases, but not the same sequences as DNA’s triple-base “letters”. Arduan life is based on proteins, which like your proteins are assembled from amino acids, but not from the
twenty specific aminos used to construct your body, rather from an overlapping, non-identical set of twenty-four acids. Arduan life seems to rely on some genetic coding being stored in the proteins
themselves – as if the genetic information is more distributed. This may help make the coding more flexible in the case of changing climatic conditions . . .

‘On the other hand, Yuri Eden, life on Mars is based on a variant of DNA much
closer
to Earth’s than the Arduan system, and a more similar protein set. You can see the
implication. Earth, Mars, Per Ardua – all these families of life are related. Mars is a more recent branching from Earth. Or vice versa.’

‘Or it all branched off from what’s here, on a world of Proxima.’

‘Yes. This is panspermia, Yuri Eden. A lovely idea, of life being carried through space, presumably in drifting rocks, blasted up by impacts from the surface of planets. The worlds of a
solar system, Earth and Mars, say, or Per Ardua and the Pearl, may readily share material. But it is much harder, more rare, for material to be transferred between star systems. Whatever came here
from Earth, or travelled from Per Ardua to Earth – or came from a third source entirely – came long ago, deep at the root of all the life forms on all the worlds. I imagine a panspermia
bubble spanning the nearby stars, Sol, Proxima, Alpha A and B, perhaps others further out, all sharing the same basic chemistry. Beyond that, maybe there are other bubbles, of other sorts of life
chemistry – perhaps nothing like our own at all.’

‘And out of all that comes something as curious and busy as a builder.’

They were close to the forest fringe now. They came upon a garden of particularly large stromatolites, towering hemispheres each with a hardened carapace the colour of burned copper. They
trudged on, parallel to the stromatolites and away from the track.

The ColU swivelled its camera eyes to study Yuri. ‘You have noticed that too. About the builders. That they display curiosity.’

Yuri shrugged.

‘None of the others have noticed this, or if they have it has not been remarked to me.’

‘So what?’

‘Similarly, Yuri Eden, you try to puzzle out the transits of the inner worlds, while the others barely look up at the sky . . . You ask why I was made curious. Why are
you
curious, Yuri Eden?’

‘Why shouldn’t I be?’

‘The others aren’t. Not even Lieutenant Mardina Jones. You have all suffered huge trauma. You, in fact, have suffered more, having been sent away from your own time even before your
exile here. And yet here you are, thinking, observing, watching the planets, the life of Per Ardua. You can speak to me openly, Yuri Eden.’

Curious about builders or not, Yuri didn’t like to look too deeply inside himself. He said uncomfortably, ‘I don’t think of it like that. It just feels like I keep getting
pushed through these doors. From past to future, Earth to Mars, Mars to the
Ad Astra
, the
Ad Astra
to here. Or when things change. When people die, when Onizuka and Harry went
crazy. That’s like we passed through another kind of door.’

‘And?’

He shrugged. ‘And I can’t go back. I know that. I can’t bring Lemmy back to life. I can’t go back to the past. Every door I pass through is one way. So I may as well look
around, and see what there is beyond the next door, and the next.’

‘Hm. If you can’t go back, why won’t you reveal your true name to your fellow colonists?’

‘Why should I?’

‘That itself is a reaction to your past.’

He had no answer to that. They moved on for a while, walking, rolling, in companionable silence.

They came to one of the ColU’s experimental sites. This was an outcropping of rock, a black basalt, volcanic rock that had erupted in sheets from the sandy ground after some ancient
magmatic event. They called this extrusion feature the Lip. Here the ColU had fenced off an expanse of bare rock, perhaps a quarter of an acre, and domed it over with a fine transparent mesh to
keep out the native life. Lichen were growing busily on the naked rock, powdery white spots.

The ColU inspected this lichen garden, with sensors mounted on a manipulator arm.

‘It’s doing well,’ Yuri said.

‘I think you’re right. I’ve used a variety of lichen here, some gen-enged, some a hybrid with cousins from Mars. But some of this is transplanted straight from Earth, from
Antarctica, from the high deserts, from post-volcanic landscapes where lichen such as this would be the first colonists. What remarkable organisms – and themselves complex, a symbiosis
between fungi and photosynthesising bacteria. They dissolve the rock for access to nutrients like phosphorus; they grow filaments to break up the rock, and later the mosses come and grow in the
dust, and then plants . . . I did not manufacture these patches of nascent soil. The lichen are doing it for themselves. How remarkable, Yuri Eden – if you’re curious about anything, be
curious about this!
These
are the true invaders of Per Ardua, the true colonists—’