Stargazers in parts of Europe were stunned by an unusual sight on Monday evening: a large, glowing blue spiral in the sky.

Kelvin Helmholtz clouds are named after the two scientists who studied the physics behind them A rare cloud formation resembling waves in the sky has been seen across North Yorkshire. The billowy ...

You know that beautiful, clear blue sky over Rochester? It’s always a welcome sight—when it happens. But have you ever noticed the thin white streaks that sometimes crisscross the sky? Many people ...