There are still mysteries

Try this: Starting at home, drive, run, ski, or walk about fifty thousand feet. That would be about ten miles, or 15 kilometers. It won't take you long (especially if you drive) and chances are, when you get there, it will be a place at least vaguely familiar to you. At the very least, it will be a place that is qualitatively familiar to you. Even if you end up in a strip mall, or a government office building, or a recreational park, that you've never been to before, you'll be able to find your way around.

Now do the same thing, but instead of going across the landscape, go straight up. What a difference! You wont be able to breath, you'll freeze to death, and there will be fewer strip malls (probably).

Up there is where hail storms and tornadoes, and lightening and other atmospheric phenomena that we actually understand very poorly live (to that altitude and below). It is intersting to contemplate the degree to which we don't understand as much as we'd like to in that zone of this planet, not very far away.

Now look at the picture above. This is a photograph ... among the first photographs ever ... of a phenomenon that occurs somewhat farther ... about 75 kilometers above the earth's surface.

The first observations of these "night-shining" clouds by a satellite named "AIM" which means Aeronomy of Ice in the Mesosphere, occurred above 70 degrees north latitude on May 25. People on the ground began seeing the clouds on June 6 over Northern Europe. AIM is the first satellite mission dedicated to the study of these unusual clouds.

These mystifying clouds are called Polar Mesospheric Clouds, or PMCs, when they are viewed from space and referred to as "night-shining" clouds or Noctilucent Clouds, when viewed by observers on Earth. The clouds form in an upper layer of the Earth's atmosphere called the mesosphere during the Northern Hemisphere's summer season which began in mid-May and extends through the end of August and are being seen by AIM's instruments more frequently as the season progresses. They are also seen in the high latitudes during the summer months in the Southern Hemisphere.

Click the picture to read about it on the NASA web site.