The scene at Pic du Midi is one out of a sci-fi movie: a fortified concrete-and-stone complex, packed full of metal domes, sprawls across the top of a precipitous peak above the clouds.

It’s a lenticular cloud over Antarctica, November 24, 2013. These lens-shaped clouds are often mistaken for UFOs. Here how they form, plus the best in photos and video.

Noctilucent clouds usually form close to the poles, but in recent decades, they’re being spotted closer to the Equator ...

The nacreous clouds lit up the skies above Norway, and Alister Doyle captured them from his home in Oslo. Breaking space news, the latest updates on rocket launches, skywatching events and more!

This means PSCs can form much higher up than normal clouds, between 9.3 and 15.5 miles (15 to 25 kilometers) above the ground ... lights in Alaskan skies (photos) On Jan. 25, extreme freezing ...

are the highest clouds in the atmosphere, sitting at a height of 50 miles above the earth. The National Weather Service Seattle tweeted the photos below just after 4:15 a.m. Friday and said ...

The clouds were spotted on Jan. 17, and the photos were taken over the course ... by Curiosity are at an altitude of 37 to 50 miles above the planet's surface. Other images show the clouds as ...

Sometimes, dust and water vapor also blend in, helping craft linear rows of clouds like those spotted hovering above a vast swath of lowlands near Mars' north pole known as Vastitas Borealis.