Circumstance

"Contact with the entire Epsilon Eridi System has been lost. We have been given confirmation that the military centres on Reach have been glassed from orbit, and our defense group on Circumstance have failed to complete Operation: LAST STRAW. By 1740 today, all communications from Circumstance, Taralus and Tribute have ceased, likely due to those colonies being glassed by the enemy fleet from Reach"

- A prowler report from the ONI Razor, reporting on the destruction of all human colonies in the Epsilon Eridi System in late 2552

Before its loss in August in 2552, the was one of the very most important systems to the UNSC's war effort - it was, after all, home to their headquarters on, and provided a navigational gateway to the  system where humanity's homeworld of  laid. Yet while it is an undeniable fact that Reach was the most notable and important planet of the system, it is completely inaccurate to say that the other colonies had little to no importance besides to house human colonists. Circumstance, the centre of Law and justice in human space, was one example of how central it was to the continuing survival of the UEG.

The furthest planet from the body of which the system is named after, Circumstance was naturally one of the hardest planets to tame in the earliest period of humanity's colonial efforts. When it was discovered, it had a far thinner atmosphere than its size suggested, an extremely cold climate which rarely circulated because of its frozen oceans and an inactive lithosphere which meant its soil was extremely poor in nutrients, even if it was defrosted. Yet despite these extremes, the initial colonial efforts prospered, stabilising the atmosphere with millions of tonnes of Carbon Dioxide, Nitrogen and Oxygen to make it even vaguely habitable. Once these measures succeeded, Circumstance's advantages, both due to its makeup and its position, were good enough to establish a profitable business in both Mining and Politics, though its Political and later Entertainment industry lasted far longer than the ill-managed mining was to. As the seat of power for the Eridi Alliance of Free Trade (EAFT), the respected High Court of the Inner Colonies and finally the Epsilon Eridi Government, it was a major reduction and strain of the UNSC's resources when the planet was glassed in 2552.