Europa Oceania

[gamblix]

Europa is rotating synchronously around Jupiter. She does - like our Moon - show ever the same side to Jupiter. So why should there be any kneading at all? The icy sphere should not be cracked by tidal forces because there are no such forces.
All that one should be able to observe is a slightly distorted sphere with one bulge towards Jupiter (pulled gravitationally) and another one (driven centrifugally) at the opposite side.
And a theoretically rotating core at different speed inside should not have much mechanical effect on the outer sphere.

Am I right so far?

But two nested rotating magnetic bodies at different speeds can produce an electric field. Maybe there's a diamagnetic effect creating an opposite magnetic pole inside the icy sphere? Or the icy sphere contains a lot of permanent magnetic iron and nickel material from meteorites. If so, Europa would be an electric generator. And because there's no load, the electric field would discharge now and then ...

Although I am able to imagine the emergence of electron filaments like in lightnings or CRTs I have difficulties to envisage why those filamental discharges should not be quasi chaotic like lightnings but create those cycloid shapes.

On the other hand - how much mechanical distortion could arise off a diamagnetical effect inside the icy sphere?

[Sparky]

Europa is rotating synchronously around Jupiter. She does - like our Moon - show ever the same side to Jupiter. So why should there be any kneading at all?

Is the obit elliptical ? if so, would that produce kneading?

much prefer the remainder of your post for an explanation...

[gamblix]

@sparky

Good question.
Tidal forces are the result of different forces acting at the same time on the same body in partially different directions. You have two orbiting bodies, one rotating body a gravitational pull and a centrifugal repulsion. The centrifugal part is caused by the rotation of both bodies around their common center of gravity. Because that center is inside jupiter, there's only a tidal force effective on jupiter, not on Europa. And because Europa isn't spinning inside Jupiter's gravitational grip any more there's no breaking force, too.

In case of the elliptic orbit you have only the gravitational pull, no resulting centrifugal tidal force.
It' just like with a yoyo, up and down, the whole body. No part of it is accelerated or decelerated at a different rate so there's just no force to accomplish kneading (e.g. shearing forces)

You might want to look at this animation:
http://de.wikipedia.org/w/index.php?tit ... 0225114907
The tidal force is concequence of the gravitational force not a direct result.