"THANK WHY" = Think Y
"Sealed Tight" = S T.
YST = Yukon Standard Time (-9 hrs GMT)
Someone was looking at the volcanoes at the end of the Aleutian Islands, but maybe the pics were taken somewhere around the Yukon coast and the missile is the unknown object?
3:56 AM Pacific time for the missile launch. Got a time stamp for those pics from Q?