Johann Franz Encke

So I went back to the Cassini archives to look for a, l- some cool image, and I came across this image that was taken in '08.

It looks at the rings of Saturn and it specifically looks at the Encke gap, which is one of the largest gaps in the ring, and in that ring there's a moon that circles within the gap.

It's called Pan.

Uh, Pan is very unusual.

It is different with the smaller bodies of our system.

Encke in particular has shown, with reference to the well-known small comet which bears his name, that it circulates round the sun in ever-diminishing orbits and in ever-shorter periods of revolution.

Its motion is similar to that of the circular pendulum which we have mentioned, and which, having its velocity gradually delayed by the resistance of the air, describes circles about its center of attraction which continually become smaller and smaller.

The reason for this phenomenon is the following.

As the force of their motion diminishes, they yield by a corresponding amount to the attraction of the sun and get nearer to it.

If the resistance continues, they will continue to get nearer the sun until they fall into it.

Encke's comet is no doubt in this condition.

But the resistance whose presence in space is hereby indicated must act, and has long continued to act, in the same manner on the far larger masses of the planets.