- Oct 2010
I have never see oe till tonight.
June 2019 has been a beautiful month so far for seeing noctilucent – or night-shining – clouds. The Facebook group Noctilucent Clouds Around the World has been buzzing with sightings, and loaded with photos, and we’ve also heard from people who sighted the clouds this month from farther south than usual, including some sightings from as far south as Oklahoma. Spaceweather.com reported a big outbreak of the clouds on June 8 and 9, saying:
… many people who have never previously heard of noctilucent clouds … found themselves eagerly taking pictures of them – from moving cars, through city lights, using cell phones and iPads.
On June 8 and 9, people were reporting more southerly than usual sightings of the electric-blue clouds, but, really, this whole month has been fine for seeing them.
What are these clouds? They’re seeded by dust from meteors. They’re the highest clouds in Earth’s sky, floating more than 50 miles (80 km) above Earth’s surface. You know how – at the end of day – a high mountaintop may be the last thing illuminated by sunlight? So it is with these clouds. Sunlight can be striking them when it has long set for us on Earth’s surface, and thus they are noctilucent (noct + lucent = visible or glowing at night). Plus the clouds are cold and contain ice crystals. When sunlight strikes them, they shimmer and glow with a bright blue color.
Once seen only at high latitudes – relatively close to Earth’s poles – scientists have said the clouds have been edging southward in recent years. No one knows why.
More: Noctilucent Clouds