A ten meter object at 100,000 miles is smaller (by angular diameter) than an atom at arms length.
100,000 miles is on our doorstep & objects in freefall into Earths gravitational field are generally traveling at speeds of between 5 & 50 miles per second. Unless they are cometary, they are almost completely black. Against the black background of space. They reflect very little infra red.

Invent a machine that can see objects like that at a distance that will give us time to calculate where & when they will impact. Collect Nobel prize for physics. Retire with free hookers & beer. Invite me to the party.