Now, to be fair, we’re basing that hypothesis on the Lawki data, which represents only a handful of planets. We would need a larger sample size to be sure.

If you are a person of science – whether it be your career or your hobby or a passing interest – I would imagine this fact ignites you as it did us. We haven’t answered the biggest Why yet, but damned if we didn’t get a step closer.

But what if science isn’t your world? I admit, I don’t know whether people outside of my social sphere would care about this at all. I’ve spent my entire adult life embedded with scientists and the people who love them. I take it for granted that this sort of knowledge is cherished, is yearned for. And I am keenly aware that in order to tell you what we found, it required a thousand words of explanation before I could get to the crux. Is this discovery of ours too obtuse? Did you skim through the science in search of the point? I won’t judge you if you did; I’m genuinely curious. Facts about amino acid chirality will affect nothing in your daily life. They won’t put food on the table. They won’t build a roof over your head. They won’t strengthen your relationships or keep you healthy or help you do your chores. They change nothing about the everyday. But what I hope is that when you’re lying in the dark and wondering – when you’re asking that big Why – what we found will help you fall asleep with the comfort of a little more context than you had before.

Does it? Or am I wrong? Are we out here chasing useless things? I can’t escape my bias, just as my cells can’t use right-handed amino acids. I want to know whether you care about our arcane work in the sky, given your immediate struggles on the ground. I will not be upset by the answer. I just want to know. All of us aboard the Merian want to know what you want of us.

So, here’s how this is going to go.

After I finish writing this, and after my crewmates give it their approval, and after we send the file back to Earth, we’re going to finish our remaining three-and-a-half years on Votum. After that, we’re going into torpor.

Where we go from there is up to you.

I’ve reconfigured the Merian’s torpor system so that it will keep us asleep until the craft receives a message from Earth. We’ve provided the technical transmission instructions separately, but essentially, the Merian will be awaiting a simple yes or no.

‘Yes’ sends us to Tivael.

‘No’ takes us back to Earth.

If we receive no answer, we’ll remain in torpor until old age or equipment failure takes us.

We are comfortable with any of these scenarios.

What we want you to ask yourselves is this: what is space, to you? Is it a playground? A quarry? A flagpole? A classroom? A temple? Who do you believe should go, and for what purpose? Or should we go at all? Is the realm above the clouds immaterial to you, so long as satellites send messages and rocks don’t fall? Is human spaceflight a fool’s errand, a rich man’s fantasy, an unacceptable waste of life and metal? Are our methods grotesque to you, our ethics untenable? Are our hopes outdated? When I tell you of our life out here, do you cheer for us, or do you scoff?

Are astronauts still relevant in your time?

We have found nothing you can sell. We have found nothing you can put to practical use. We have found no worlds that could be easily or ethically settled, were that end desired. We have satisfied nothing but curiosity, gained nothing but knowledge.

To me, these are the noblest goals. The people who sent us here believed the same. But if you share that belief, do you understand that we might fail? You must understand the cost here – the reality of what we do. Because sometimes we go, and we try, and we suffer, and despite it all, we learn nothing. Sometimes we are left with more questions than when we started. Sometimes we do harm, despite our best efforts. We are human. We are fragile. Are we who you want out here? Would you be more comfortable with the limited predictability of machines? Or is the flexibility of human intelligence worth the risk of our minds and bodies breaking?

We believe the potential answers are worth the challenges. We do not know what you believe, what Earth believes. And ultimately, it is Earth that sent us. Four people alone cannot decide whether it is right for us to venture further into the galaxy, desperately as we want to. I don’t operate under the delusion that OCA represented – represents, if you’re still there – all of humanity. But space travel is a grand enough venture, a daunting enough task, that it requires the dedication of the many, not the mere fervour of a few. We are four. It took the work of thousands to get us here, and the resources of thousands more. Our days out here have been largely autonomous, but we live within a home that was lovingly built by other hands. Everything we do, we do on the shoulders of others. And for that reason, a consensus of four is insufficient. If no one is listening, if no one cares, then we would be staying out here only for ego. We will have abandoned you, and that’s unacceptable to us.

We are ready to live out our lives without ever seeing Earth again. We’re happy to do it. It is the most natural end I can imagine, the best death I could hope for. But we can’t accept that fate if no one is ready to pick up where we left off. If we die out here with your blessing, then we die as your family. If we die without it, we die alone. And if that is the case, we would rather come home. We feel it is better, in that scenario, to spend our remaining years in your company, sharing our stories in the hopes that we might relight the spark. Either way, we will carry this torch. All we’re asking is: where will it burn brightest?

We leave that question to you.

As the Secretary General of the United Nations, an organisation of one hundred and forty seven member states who represent almost all of the human inhabitants of the planet Earth, I send greetings on behalf of the people of our planet. We step out of our solar system into the universe seeking only peace and friendship – to teach, if we are called upon; to be taught, if we are fortunate. We know full well that our planet and all its inhabitants are but a small part of this immense universe that surrounds us, and it is with humility and hope that we take this step.

– Former UN Secretary General Kurt Waldheim, 1977, as recorded on the Voyager Golden Record

Acknowledgements

Like Ariadne, I’m not a scientist. I have no experience in that field of work, nor any formal education within it. Science fiction is my transformative fandom, and as in all heartfelt fic, I revere the canon but play fast and loose with details of my choosing. Still, for this book, I wanted to be as close to the mark as the story would allow, and to that end, I received some help that deserves proper thanks.

In early 2018, I was a guest at the Melon conference in Hong Kong, and it was there – at a welcome reception, blindingly jet-lagged – that I met Lisa Nip, a PhD candidate at MIT Media Lab with a bold goal: using synthetic biology to solve the challenges of human space travel. She gave a talk on that topic the next day, and I sat in the audience, still jet-lagged but on the bleeding edge of my seat. Her vision of genetic engineering as practical supplementation, rather than dystopian eugenics or transhumanist evolution, is one I found both radical and beautiful, and without her blowing my mind wide open, this book wouldn’t exist at all. Lisa took the time to Skype with me from her lab while I was in the early stages of figuring everything out, and I am enormously grateful for her generosity and patience in walking me through her science and the possibilities therein. If anything in this story strays too far from the realm of reality, that’s a reflection of me coming at this from the sidelines, not of her fine teaching.