The bottle shape apparently was caused by the aircraft first making contact with the earth out there at the neck of the bottle, sliding toward us and forming that larger areas as it came to rest.
12 seconds sound clip from the The Thing from Another World movie soundboard.
You can hear this line at 00:18:00 in the Blu-ray version of the movie.
Quote context
[...]
- There we are. Holy cats! What a weird-looking thing.
- Let me get a picture before you track up the whole place.
- This Geiger counter's going crazy.
- Something's melted that surface crust.
- It's frozen over again into clear ice.
- What could melt that much ice?
- Take the dogs over on that side.
- Could an airplane melt that much ice?
- One of our own jets generates enough heat to warm a 50-storey office building.
- It's part of an airfoil... probably a stabilizer of some sort.
[...]