Why is it so inevitable that someone must come in and remind us that UFO != alien craft whenever there is a thread about UFOs? A UFO (in the common use of the term) is almost certainly <i>not</i> a foreign airplane, satellite, weird meteor, etc, because the cases that continue to be called UFOs generally are of objects that portray aerodynamics that are beyond any known sources. So yes, UFO does not mean alien craft, UFO means &quot;some crazy ass shit that is almost definitely not something we understand&quot; -- pointing out the distinction does not somehow neutralize the mystery of the cases that persist to this day (like the Belgian one in this article.) The &#x27;extraterrestrial hypothesis&#x27; is certainly an attractive one to try to rule out for these cases, but nobody presumes to think it&#x27;s the only one worth considering.