The sky IS falling (daily, on Io)

Chicken Little wouldn't be wrong on this moon of Jupiter.

Every day, as Io slips into the shadow of the mega-planet, its atmosphere (primarily composed of tenuous sulfurous gases vomited from within, where it is squeezed by the tidal forces of Jupiter) gets colder.  In fact, it gets cold enough to snow -- which has the effect of reducing the atmosphere to nothing.  When the surface of Io gets re-warmed by the distant energy stemming from the Sun as it emerges from the shadow, the sulfurous snow becomes gaseous again.

Every orbit.

This is termed "atmospheric collapse" by the planetary moonologists.

We just term it very unusual -- and very interesting.

This phenomenon is further explained here:

Scientists observe Io's atmospheric collapse during eclipse