(WFLA) — Stargazers in parts of Europe were stunned by an unusual sight on Monday evening: a large, glowing blue spiral in the sky ... instantly froze at the high altitude.

Noctilucent, or "night-shining", clouds can be seen on Mars, just as they are on Earth. Nasa's Curiosity Mars rover imaged these high-altitude clouds ... sight in the sky above the UK.

On a tranquil summer evening, just as the sun dips below the horizon and darkness begins to settle, an ethereal spectacle ...

The UFC is known for its spectacular fights, but this time around they wanted the fight to be high-flying as well ...

Clouds are a fascinating part of our sky, made up of countless ... three main groups based on their altitude: cirrus, cumulus, and stratus. Cirrus clouds are high-altitude clouds, often appearing ...

We haven’t figured out exactly what gives them their shape, determines altitude – or makes them rain when they do. But ...