I recall reading an article where the moonmoon, could be detected via radarradar and that orbiting radar satellites could map out the surface of marsmars, and in some cases even parts of Venus (the lattermost might be a false memory).
I am curious, what would be a large enough radar to put into space (and perhaps also at what distance from the sun), that would allow us to detect MOST Kuiper beltKuiper belt objects, SednoidsSednoids, and the Oort CloudOort Cloud. Is this the kind of thing that could be afforded under $\\\$100\times 10^9$?