Noctilucent clouds, a new heavenly phenomenon- should we ask WHY it's new?

[Deja Q]

http://science.nasa.gov/headlines/y2003/19feb_nlc.htm

"Noctilucent clouds are a relatively new phenomenon," says Gary Thomas, a professor at the University of Colorado who studies NLCs. "They were first seen in 1885" about two years after the powerful eruption of Krakatoa hurled plumes of volcanic ash as much as 80 km high in Earth's atmosphere.

Eventually the ash settled and the vivid sunsets of Krakatoa faded. Yet the noctilucent clouds remained. "It's puzzling," says Thomas. "Noctilucent clouds have not only persisted, but also spread." A century ago the clouds were confined to latitudes above 50o; you had to go to places like Scandinavia, Russia and Britain to see them. In recent years they have been sighted as far south as Utah and Colorado.

Started with one epruption but they've spread. Could this tie in with pollution?



I'm going out tonight, maybe I'll get lucky. If not, I'll go to a bar and still not get lucky...

[BattyDem]

1. It may be a sign that we've really f*cked up the environment ...

but it certainly does look cool! :D

[obxhead]

2. couldn't possibly be pollution

nope not a chance
no way in hell

BTW
I'm going out tonight, maybe I'll get lucky. If not, I'll go to a bar and still not get lucky...
with that attitude luck will never follow. wish ya well

[Rick Myers]

3. That's the second thing I've heard of this week

that I'd NEVER heard of... Strange.

[BrklynLiberal]

4. Never heard of it before either....but I think I have seen it

Noctilucent clouds (also known as polar mesospheric clouds) are rare bright cloudlike atmospheric phenomena visible in a deep twilight (the name means roughly "night shining")....

[havocmom]

6. here's a site that will show you some swell stuff

http://www.spaceweather.com/

They have an email service you can sign up for. Will let yo know when there's cool stuff going on in the sky. They also have a gallery where people upload photos. Always good to look when there's been auroral activity.

[BrklynLiberal]

7. Thanks. That is great.

[iconoclastic cat]

5. Watch out for this guy: