Noctilucent Clouds... Nature's Shy Beauty

Over the South Pole, it is still noctilucent cloud season! Noctilucent clouds (NLCs) there are spreading and brightening. Below is an image taken at the end of November from NASA's AIM spacecraft showing the colorful display over.

Figure 1. Satellite Image over Antarctica taken on November, 27th.

The season for these beauties over the southern hemisphere began on Nov. 22nd with just a few puffy clouds over the frozen continent. NLC's can develop and multiply rapidly once they first appear. If you're unfamiliar on the type of cloud that is foreign to our area of the world, they are truly a beautiful sight. For the best chance of seeing these shy clouds, you need to look high up in the far northern & southern latitudes, usually during dawn and dusk with the aid of the setting/rising sun light display.

So, what are noctilucent clouds? Below is an image showing off one instance of its brilliant display.

Figure 2. Image of noctilucent clouds AFTER sunset. Notice how lit they are, even when the sun is WELL BELOW the horizon.

Noctilucent (meaning night shining in Latin) clouds are composed of tiny ice crystals present as high as clouds can be in Earth's atmosphere (sometimes above 50 miles or ~85 km!). They are the highest cloud group that we have on the planet.

Their domain is over the highest latitudes on Earth. The closer to the poles you travel, the better that chances of seeing them will be. But even traveling north through Canada or hiking through the Andes south along South America will not guarantee a successful sighting of these bashful clouds. They are NORMALLY too faint to be seen. There are only two, pristine times of the day to view them... around dawn and dusk (better time), assuming that the viewable sky is clear enough to look 50+ miles up.

NLC's are unique, in that they are only revealed to the observer (you) when sunlight illuminates them from BELOW THE HORIZON. Fast Fact: This is the only species of cloud that is always better to see when the sun is below the horizon.

Figure 3. Showing how to properly view NLC's. Image courtesy theflatearthsocity.org

Figure 3 shows how you can properly see these clouds. In fact, it all boils down to mathematics. Since these clouds are so high up the elevation scale in the sky... you could be looking well over 100 miles up and out toward the cloud, with the sunlight coming from below the horizon. Very cool!

Happy almost Friday,

Joe