Noctilucent Cloud Sightings
skies above Newcastle, Country Durham and Northumberland
Since June began, sky watchers have seen noctilucent clouds over Ireland, Sweden, Denmark, Scotland and Russia. And more are in the offing…. Data from NASA’s AIM spacecraft have shown that noctilucent clouds (NLCs) are like a great geophysical light bulb. They turn on every year in late spring, reaching almost full intensity over a period of no more than 5 to 10 days. News flash: the bulb is glowing, and it is definitely electric blue.
Noctilucent clouds first appeared in the 19th century after the eruption of super-volcano Krakatoa. At the time, people thought NLCs were caused by the eruption, but long after Krakatoa’s ash settled, the clouds remained. In recent years, NLCs have intensified and spread with sightings as far south as Utah and Colorado. This could be a sign of in Earth’s atmosphere.
Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
June 4, 2015 at 6:42 pm
Reblogged this on Modern Astronomy.