The Evacuation of Earth was an evacuation of the governing personnel of the Confederacy of Borealis, along with about 25 billion out of its population of 28 billion. It began on October 20051, and is believed to be one of the densest movement of population in the history of humanity. It was primarily caused by an impending Kessler Syndrome which was in itself caused by a massive, continuous space combat in low orbit as a Commonwealth attempt to take the planet.
The homeworld of humanity, the Earth has always been one of the most populated systems until a population control measure was put in place to ensure the safety of the planet. Nevertheless is still hosted some 30 billion humans and other sentient species, not accounting for the visitors and traders which come in large numbers. Despite technological advancements, the population was well above the maximum amount which can be supported using resources available on the planet, which made Earth reliant on imports of food, metals, machinery, and other goods.
Politically, the Earth is one of the most important locations within the Virgo Supercluster due to it being the capital of the CoB. It had a massive military presence in orbit, which allowed it to easily repel raids during the Galactic Wars. However, in the 20000s, as the Confederacy of Humanity split, some of these military resources were allocated elsewhere. This attracted a massive invasion by a faction of the rebellion known as the Commonwealth of Autonomous Spacefarers. While they managed to capture large parts of Sol and gained some ground in land combat on Earth itself, they were eventually repealed.
During the Confederacy counterattack to push away the rebel fleet, it was estimated that close to 100,000 ships were destroyed from both sides, not including the missed railgun projectiles and station shrapnel. Large fragments of the ships tend to collide into each other, resulting in thousands of small-sized pieces each. These cause extreme hazard for any form of navigation, due to the difficulty in both detection and evasion.
Immediately after the CAS had retreated the CoB setup an operation to clear up the debris. However, they discovered that it was simply impossible to clear the debris field faster than it could self-expand and that it may take several centuries from the point where the low orbit would be too hazardous to navigate until it recovers. Therefore, an evacuation was put forward and was accepted by the CoB, reluctantly.
After ensuring that there were no hostile threat, the CoB began to move the central government officials and crucial articles out from Earth to a temporary center of governance in Cronosopolis, Saturn. Then the civilian population was slowly evacuated using cargo freighters, passenger ships, and military vessels alike, leaving only those who fervently wished to stay on Earth (approximately 3 billion people). Those left behind were only subject to small-scale physical contact with the rest of the system although they could still communicate easily.
Due to Earth's economic position and situation, those who were left homeless were not those of low income - plenty of the 25 billion were quite well-off, which allowed them to finance their own mini-colonies for themselves throughout the still-unoccupied systems or sparsely populated planets within 200 to 500 light-years from Sol (the Middle Sphere). Some of these colonies grew into sizable cities, although they still swore allegiance to the Confederacy.