What they Ran Out Of
Mercury knew it first. When the Earth suspended shuttle service and signed off with "please forgive us," Mercury imported two-thirds of its food. With rations, the average caloric intake dropped to 800 calories per day with no end in sight. There were culls. There were conflicts. There was cannibalism. They needed a miracle.
The Asteroid Miners knew it too, but they had ships. They called every family back to Ceres and Vesta and organized convoys, pooling what food they had, what oxygen. They set out for the nearest two planets that could take them: Mars for those at Ceres, Venus for those at Vesta.
Venus had food. They had farms. They'd maintained strict population controls to keep themselves close to self-sufficiency. They still panicked. They'd lost their connection to the homeworld, and they didn't know how to mourn. It took the quick actions of one man to stop the riots, and appeal to everyone's sanity. Venus recovered, though it still mourned.
Mars prepared itself. With food and farms, the largest population and the easiest environment to plunder, it built to become the new prosperous centre of the solar system. It had robot drones to trade with Venus. It kept the dream of a human solar system alive, but with the same doggedness that had condemned the Earth.
The Jupiter Moon outposts had less food than Mercury. They were research stations and speculative ventures, with scientists drilling through the ice looking for life funded by business people looking to cash in on humanity's leap to the outer solar system. They knew they couldn't survive or go home. They continued their work and radioed what findings they could. They ran out of time. Both went as silent as the Earth.
Beyond the Moons of Jupiter, there were only robots, sending back messages about what they were seeing, to a planet that could no longer hear.