How did you know it wasn't a plane, just not one that was landing?
You said yourself that the ones you were comparing it with were in a different part of the sky, so this was seen from a different angle and distance.
Reductionist and proud of it.
Being ignorant is not so much a shame, as being unwilling to learn. Benjamin Franklin
Chase after the truth like all hell and you'll free yourself, even though you never touch its coat tails. Clarence Darrow
A person who won't read has no advantage over one who can't read. Mark Twain