The Arrows of Time

‘That doesn’t bother me,’ Agata said firmly. ‘I’ve stolen an advantage over everyone on the Peerless, squeezing three years into each year that passed for them. If they end up deriving some beautiful corollaries from my results by the time I return, that will give me the best of both worlds: I’ll get to see what other people make of my work – and I won’t even have to wait around while they do it.’

It was a nice idea in principle; maybe she really could live up to it. But whether or not her competitors had already had the last word, she was hungry to return to her calculations, reinvigorated by this proof that her efforts so far had not been wasted.

Tarquinia said, ‘Make sure everything’s secure in your cabins. I’ll need to run the engines hard for a while; we still have a lot of velocity to shed before we can go into orbit around the planet.’

Agata said, ‘Right.’ The shape of the cosmos would have to wait; there was still the small matter of Esilio.

21

While Azelio and Tarquinia debated the merits of different landing sites, Ramiro clung to a rope beside the window and gazed down at the starlit world below. How could he understand Esilio? Of all the sciences he’d studied as a child, geology had been the least developed – and at the time, he’d imagined, the least likely ever to be of use to him. Of the little that he remembered, he remained unsure what he should trust. The ancestors had had no idea what a rock was actually made of, while their successors, with all their superior knowledge, had never set eyes on a planet.

‘We need to be within walking distance of four or five different kinds of soil, or what will the crop tests be worth?’ Azelio said heatedly.

‘I appreciate that,’ Tarquinia replied. ‘But if we don’t come down on flat, stable ground, we could damage the Surveyor irreparably.’

Over the eons, Ramiro had been taught, every kind of rock exuded traces of gas, and for a body with sufficient gravity this gas would accumulate into an atmosphere. If the body also happened to orbit a star, winds driven by the temperature difference between day and night eroded the rock, and once there was airborne dust and sand that accelerated the process. The routes of the dust-flows carved out valleys and mountains, shaped as well by the differing durability of the underlying rock. But where had those various minerals come from? As far as he recalled, no one even knew for sure whether they dated all the way back to the entropy minimum, had formed over cosmic time from the sedate decay of some primordial substance, or had been forged in the core of a giant ur-world where liquid fires – contained for a while by its unimaginable gravity – thrashed and churned until the whole thing finally split apart and scattered.

Tarquinia brought an image of the next candidate onto her console, taken in full sunlight with the time-reversed camera. Ramiro struggled to interpret it, but the combination of near-smoothness and suspiciously delicate ridges suggested a plain of wind-ruffled dust into which the Surveyor might sink and vanish.

‘Can’t we just settle for the safest-looking ground?’ he proposed. ‘If it turns out that there’s a problem with the soil, we can always ascend and come down somewhere else.’

Azelio turned to stare at him angrily. ‘I’m not spending years hopping from site to site! That’s not what we agreed to!’

‘All right. Forget it.’ Ramiro regretted speaking so carelessly; Azelio had his niece and nephew to think of.

Tarquinia summoned another image. ‘Why do we only have two probes?’ she fretted. They could send one down in advance of the Surveyor, and the second if their first choice proved unsuitable, but that was the limit: the probes weren’t sophisticated enough to explore more than one location each.

‘Perhaps we could extend the survey for a few more days,’ Ramiro suggested. The planet was turning beneath them as they circled from pole to pole; each successive orbit carried them over a different meridian, and though they’d sampled a wide variety of terrain they were still far short of seeing everything. ‘There has to be a perfect site down there.’

‘Exactly!’ Azelio replied. He gestured at the console. ‘None of these are acceptable.’

‘We can keep looking,’ Tarquinia agreed. ‘A few more days is nothing.’

Azelio excused himself to check on the plants. Weightlessness wasn’t good for them, but it wasn’t worth setting up the tether again – not unless the selection process was going to stretch out into stints, rather than days.

Tarquinia switched to the live feed from the time-reversed camera: dawn was breaking over a red plain criss-crossed by brown fissures.