The term "planetary nebula" has always been a misnomer, but these spectacular clouds of dust and gas may actually have something to do with planets after all, astronomers have found. When ...

Photographers—I can’t speak for everyone here, but it’s amazing to me how many of these shapes I, too, could spot in your clouds. Maybe it’s just the power of suggestion.

What the cloud maketh, the cloud taketh away. This dance of constant transformation - gas into liquid and heat into motion - that's what gives clouds their ever-changing, infinitely variable shapes.

And because the clouds change in seconds or minutes -- roiling, drifting, disappearing -- what we imagine we see changes, too. To watch the show, just sit down on the grass on a sunny day.

On a road trip from Phoenix to Washington D.C., you may notice the sky is falling — or at least the clouds are. We often admire the shapes and sizes of those overhead puffs, but the height of ...