There may be unexplained thing in the atmosphere. There obviously are, in fact.
I just doubt that it's from other civilizations in the universe.
To me, that's seeing hoofprints and guessing zebras.
Some of it could very likely be space "junk" from all the crap that we've shot up there.
Some of it could be atmospheric conditions causing light to refract, thus creating optical illusions [like puddles on the highway on a hot day; when you get there. there's none].
Then again, I couldn't PROOVE that it's not "little green people."
For reasons mentioned in my previous post, though, I just strongly doubt it.
What could survive a trip that would take so long?
If it's just mechanical like our space probes and didn't have to live that long, why wouldn't we track it earlier on its approach?
Not something I know about; just what I think.