Not everything in deep space is natural, just a few items are man-made....
Passing Pluto. In 1983, Pioneer 10 became the first human-made object to pass the orbit of Pluto, the most distant planet from the Sun.
Questions: After its launch, how long did Pioneer 10 take to get further out than Mars?
In the absence of a real EverReady Bunny, how did NASA decide to power Pioneer 10?
http://www.spacetoday.org/SolSys/ThePioneers.html/Bevin