Beauty and mystery in rare Antarctic clouds

These are really awesome pictures of rare nacreous clouds taken in Antarctica on July 25. The air temperature in the region of these clouds was -87C (-125 degrees F!), and the wind was blowing at 230 KPH (142 MPH). The clouds were located about 20 KM above the ground (12 miles).



Apparently, these types of clouds are only seen when climatic conditions are at their most extreme--such as they are now in the dead winter in Antarctica. Pretty amazing, IMHO.