The objects in the Oort cloud are believed to consist of much ice , and since the object 1996 PW was found , it is believed that rocky objects might be in the Oort Cloud . The Oort cloud is thought to comprise two separate regions : a spherical outer Oort cloud and a disc-shaped inner Oort cloud , or Hills cloud . Objects in the Oort cloud are largely composed of ices , such as water , ammonia , and methane .