Memorable nights of viewing can, however, come with many kinds of weather. For the Moon and planets, humid nights with stagnant haze or fog can actually bring the sharpest views. Even though little else is visible in the sky, planet disks appear rock steady, revealing astonishing detail.
This is called good seeing—it happens when the layers of Earth's atmosphere are calm and stable, and not mixed up by winds at different altitudes. Under turbulent conditions, the poor seeing turns the disks of planets into boiling blobs with, at best, fleeting moments of sharp views.
At most sites, nights of good seeing are often the least transparent, and vice versa. Only the finest mountaintop observatories boast the best of both worlds. Backyard astronomers soon learn to adapt their observing priorities to the conditions of the night, perhaps pursuing a galaxy hunt on a clear night, and a planet study on a night when the seeing is superb.