Question about over-cooled water?

Question

I've heard that high in the atmosphere there were found water droplets with the temperature -54 celsius (-65.2 F). How is it possible?

Answer 1

Pure water without any impurities will not freeze unless it has something to freeze on e.g. dust, smoke, other ice.

Answer 2

There is nothing for the water to nucleate on to freeze so it remains a liquid.

Answer 3

Yes, super cooled water.  Often in the tops of clouds where the air temp is below freezing the water still stays liquid.