The cloud is basically a gigantic reservoir that may hold billions of icy celestial bodies. Two of those bodies will pass by Earth in the days leading up to Halloween.

Comet Tsuchinshan-ATLAS is a Halloween visitor from the spooky Oort Cloud − the invisible bubble that's home to countless space objects

Source: space
Source Link: https://www.space.com/comet-tsuchinshan-atlas-halloween-visitor-from-oort-cloud