Astronauts onboard the International Space Station have been observing electric blue "noctilucent" clouds from Earth-orbit.

http://science.nasa.gov/headlines/y2003/18feb_nlc.htm?list760961

I wonder what your point is ??

Just wondering.

apolo

My point? I perform a valuable community service, free of charge. Enjoy it.

Interesting...didn't know about these.

I wonder if their typical formation is after one of the annual meteor showers, supporting the idea that meteor dust is seeding their growth? I guess the satellite they're sending up will help answer that.

i have been observing them over the past ten years, and have a suspision that they are indeed seeded by cosmic dust and meteoritic dust.

Very beautiful to watch. (sends chills down my spine)

fuuuunky

Still It would take a lot of dust to make a cloud glow blue. could it be light from cities below?

i imagine that 4000 tonnes of cosmic dust is collected by the earth each year...


The `blue` is the same physics as the `blue` sky

Ice crystals form around the `seed` (dust) and form very high clouds. the clouds are so high that the sun`s light can illuminate them....

( and no -it`s not the sea :) )

Ok sound good.

I wonder what your point is ??

Stop bitching. Adam gets too much shit for giving your ass information to soak up. If you dont like it, keep it to yourself and don't bitch. Thanks.

If these cause global warming, is that due to thier temperature or is it due to some light attribute? I have heard that the clouds themselves are a different temperature, but I doubt this. So, what is the temperature of these clouds versus other "clouds?"

The article says:

"Although NLCs look like they're in space," continues Thomas, "they're really inside Earth's atmosphere, in a layer called the mesosphere ranging from 50 to 85 km high." The mesosphere is not only very cold (-125 C), but also very dry--"one hundred million times dryer than air from the Sahara desert." Nevertheless, NLCs are made of water. The clouds consist of tiny ice crystals about the size of particles in cigarette smoke. Sunlight scattered by these crystals gives the clouds their characteristic blue color.

So it's cold up there.

It's also very thin, both the layer and the clouds, and they come and go, so there's likely no global temperature contribution, plus or minus.