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 summer and can be seen from the high latitudes on Earth.
Image Courtesy of NASA/Veres Viktor
There is a special kind of cloud
that is found in the mesosphere
, which is the third layer of the Earth's atmosphere. These clouds are called noctilucent clouds (NLC’s) or polar mesospheric clouds (PMC’s). Noctilucent means night-shining. The clouds are called that because they are seen best right after sunset and they glow blue-white.
Like lower clouds we see more often, NLC's are made of frozen water. They are important to study because they may be a sign of climate change on Earth, like global warming. Scientists will look into this possibility with a new atmospheric mission, called AIM (The Aeronomy of Ice in the Mesosphere).
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
Have you ever seen a noctilucent or "night-shining" cloud? Don't worry if you haven't - they are a fairly recent "discovery" in the world of science. Here's what we know! The first reporting of these eerie...more
Earth’s climate is getting warmer. During the past 100 years Earth’s average temperature rose about 0.6° Celsius (1.0° F). Things that people are doing like burning fossil fuels, changing the way land...more
Do you know what the highest clouds in the atmosphere are called? Polar Mesospheric Clouds (PMC’s)! These are very special clouds that form about 50 miles above the Earth! They are called Polar because...more
Stuff in the Polar Atmosphere There are some special things that happen in the atmosphere near the Poles of the planet. Here are a few of them. Particles from the Sun follow Earth’s magnetic field and...more
Rainbows appear in the sky when there is bright sunlight and rain. Sunlight is known as visible or white light and is actually a mixture of colors. The sun's rays pass through millions of raindrops. A...more
It takes the Earth one year to travel around the sun one time. During this year, there are four seasons: summer, autumn, winter, and spring. Each season depends on the amount of sunlight reaching the...more
Scientists sometimes travel in airplanes that carry weather instruments in order to gather data about the atmosphere. These research aircraft bring air from the outside into the plane so scientists can...more