Inner Worlds

Before the Exodus, when Humanity was first coming to the realization that they were rapidly over stressing Earth, they'd made an effort to colonize the Moon and terraform both Venus and Mars. Mercury, as close as it was to Sol, was never considered as a destination. The details of those efforts were lost to history. Like so many things lose to the past, we only had fragments. The only thing we knew with any certainty was that the efforts had, ultimately, failed.

According to the histories, the terraforming had failed on both inner worlds, and the colony on the moon never had the capacity to take more than a tiny fraction of Earth's population. There was some debate amongst historians as to whether they'd actually tried to terraform the moon, or any of the other likely targets in the solar system. Titan, Europa, Ceres, Ganymede, were all larger than some of the smaller bodies that had been terraformed in the 34 Tauri system. But the records simply weren't there, leaving us to answer the questions for ourselves.

While we would never know their minds, we could see what effort they'd gone through here at Sol before departure. Which appeared to be "not much." At least not on the scale they'd executed back home. Where there was some evidence of attempts to gravity compress a couple of small bodies, as they had to myriad moons in the 34 Tauri system, the results were less than spectacular. In the earliest days of terraforming technology the success rate just wasn't there. The recon probes would swing through the two inner gas giant systems and visit the larger asteroids to see if they'd tried to establish a presence, but we weren't expecting much.

The drones sent to Venus and Mars told a different story. Where the failure of Luna's colony was obvious, the situation on Sol's other inner world's wasn't so clear.

At its peak, Luna's colonies had probably supported two or three million people. Unlike the small bodies in 34 Tauri that had undergone gravity compression and actually supported a breathable atmosphere, Luna had always been a Black Rock. It never had an atmosphere to speak of and all of the colonies had been a combination of sealed surface structures and tunnel complexes using a mix of fusion piles and solar collectors for power.

Now though, telemetry from the drones and our own sensors showed Luna was effectively dead. There was a trickle of power from a handful of still functional solar collectors and some of the tunnels still appeared to hold atmo, but there were no signs of life or habitation. The surface team would go in, of course. That was their job. But it would be more archeology than anything else. Possibly a bit of scavenging if needed to augment our capabilities. But the man in the moon was dead and he had been for a long, long, time.

The situation on Mars was similar, though on a larger scale. While the Terraforming efforts on Mars had been primitive, they were orders of magnitude more comfortable than living in fusion sealed tunnels on an airless rock. Mars had had an atmosphere of its own before Humanity came to town and tried to make it cozy.

From the limited records and what we could see now that we were here, the Terraforming had been partially successful but hadn't remained stable. While they'd managed to get something that almost passed for a breathable atmosphere, they'd never gotten the density they'd needed to make it stick. For a while, Mars had been habitable. Folk there would have needed breathers on the surface, but they wouldn't have needed a pressure suit. And, unlike the moon, the dust wasn't going to be grinding their gear to death. It'd even rain from time to time. Wouldn't have been much, but it would have been real.

While it lasted.

We'd know more then the survey crews started to report back from Mars' surface, but we could tell from the drones alone that the Mars colony had failed. When? That was harder to say. From the little we knew so far, there'd been folks left living on Mars when the Exodus left for 34 Tauri. No telling how many, though the colonys on Mars were at least as big as the ones on Luna at their peak. Possibly as many as five or six million people. In theory, they'd had a better chance of long term survival then their kinfolk on Earth's moon. Much easier to live in thin atmo than hard vacuum. But in the end Mars reverted to its pre-terraformed state.

How long had they survived? A decade? Maybe ten? Had they tried to evacuate back to Earth, or tried to dig in and survive under hostile conditions? The survey team would tell us more. As with Luna the sensors had picked up faint power signatures, though they were probably just from some leftover equipment that was hanging on long after it should have died. According to the science team, there was a slim, but finite, chance there were still people surviving there. Though we hadn't detected any communications traffic or surface indications of life, there was the possibility colonists there had dug in and somehow managed to survive. It was a slim chance, but the survey teams would look.

Venus was a very different animal. It should have been Earth's sister world, but a runaway greenhouse effect had turned it into an inferno. By planetary engineering standards, it was ripe for terraforming. Unfortunately, according to the remaining histories, the terraforming effort there had been a failure from the start. While the equipment was in place, the harsh conditions made the process dramatically slower than anticipated and by the time of the Exodus, Venus was still uninhabitable.

What we saw now, though, was a very different picture. According to the two drones surveying Venus and our own long range imagery, it had become a living world. The details were still coming back to us, but it was apparent that the terraforming hadn't exactly failed. It had just taken a good deal longer than expected.

Why had the terraforming misbehaved on Venus? Another question the science team would answer if they could. The results of the early efforts in Sol system would be interesting to the planetary engineers back home, once the information made it to them in another forty years or so. Assuming, of course, there were any planetary engineers left at home to get the message.

Assuming we sent the message in the first place.

As with Mars, we'd know more once the survey teams had their chance on the surface. They'd be able to tell just how far the terraforming had gone and whether the planet would be suitable for life. We'd brought equipment to recolonize Earth, or another suitable world, if the opportunity arose. I don't think anyone had expected the previously barren Venus to turn out to be the opportunity we were looking at.

It was something we'd take under consideration when the time came to stay or go. We'd revisit the possibility of settling there, or on Earth, or striking out for another nearby star, or heading back to 34 Tauri. Colonization was a long term commitment separate from the commitment we'd made to the mission. One I wasn't even prepared to think about just yet.

Earth was our priority. And from here, Earth was beautiful. There were pictures in history books that showed Earth as a beautiful world of blue oceans and varied lands. The Earth of legend. Earth long before the Exodus. But that wasn't the only image we had.

There were images taken by the Exodus fleet as they left Sol system, leaving Earth behind. And those images were of a much different world. Sickly greenish brown plumes in the oceans. Barren wastelands on the ground. Browns and grays and blacks. The wreckage of cities visible even from orbit scattered across the landscape. It was the world Humanity had left behind. The world they'd ruined.

In the hundreds of years we'd been gone, Earth had apparently recovered. At least to some level. There were still areas of obvious devastation and the seas were still filled with swirls of odd colors, but the skies sported layers of white cloud and there were vast swaths of obviously regrown vegetation. Earth, in spite of being 'used up' by our ancestors, was still a living world. It appeared that life was quite tenacious.

It would be a while still before the orbiters were done with their work and we'd be ready to actually return home. Like Luna and Mars, there were faint power signatures in a few scattered locations on the surface. But none of them seemed to correspond to habitations. The most likely explanation was derelict solar collectors, or wave generators, or the last vestiges of heat escaping an ancient fission reactor.

If there were still people living on Earth, they weren't using a lot of power. If? No. Not if. There were people still alive on Earth. Even from here, we could see evidence of settlements. A few small towns. Scattered farmland. Mostly outside areas that had once been cities, but still signs of survival. The official histories had said everyone had evacuated, but I don't think anyone really believed that. Not even back then. There were just too many humans to evacuate them all. Some were bound to be missed. Some would stay behind because they didn't want to leave.

They'd inherited a ruined world, yet managed to survive. Over five hundred years later Earth's children had come home to find our brothers and sisters still hanging on. What would we find when we finally set down and came face to face with those our ancestors had left behind?

Soon. Very soon.

We would know.