The Big Nugget is the name of an asteroid that passed extremely close to Arbre, and was originally feared might impact the planet. The Big Nugget was discovered in A.R. 1107, almost a decade before it was projected at hitting Arbre. The global danger prompted the Saecular Power at that time to convene a Convox to develop methods to deflect the asteroid. Although the specific means by which they intended to alter the asteroid's orbit are not given in the novel, the Convox did develop spacecraft and hardened spacesuits for a manned expedition to the Big Nugget. From the timeline presented in the begining of the book this flight may have occurred in A.R. 1115.