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Meteor smoke makes strange clouds

A key ingredient for 'night shining clouds' comes from outer space. Scientists have detected bits of 'meteor smoke' imbedded in them.

Noctilucent clouds or NLC in 1880 and 1990 – increasing over time

They look alien. The electric-blue ripples and pale tendrils of NLCs reaching across the night sky resemble something from another world.

“We've detected bits of 'meteor smoke' imbedded in noctilucent clouds. This discovery supports the theory that meteor dust is the nucleating agent around which NLCs form.”

Noctilucent clouds near the top of Earth's atmosphere

Noctilucent clouds are a mystery dating back to the late 19th century. Northern sky watchers first noticed them in 1885 about two years after the eruption of Krakatoa.

"We found that about 3% of each ice crystal in a noctilucent cloud is meteoritic."

When meteoroids hit our atmosphere and burn up, they leave behind a haze of tiny particles suspended 70 km to 100 km above Earth's surface.

The small size of the ice crystals explains the clouds' blue color.

How methane, a greenhouse gas, boosts the abundance of water at the top of Earth's atmosphere

"When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor. This extra water vapor is then available to grow ice crystals for NLCs."
Noctilucent clouds are a sort of "canary in a coal mine" for one of the most important greenhouse gases.

"They might look alien, but they're telling us something very important about our own planet."

(NASA)