Collision between Mars and Jupiter

[billvon]

and note that since the density of Mars exceeds Jupiter's by more than a factor of 2, it occurs within Jupiter's radius, which makes calculation moot. (You could calculate it but the result has no real meaning)

However the calculation of the net gravity experienced by a point particle when Mars is about 185000 km from Jupiter center is easily shown to be zero.

OK you have a pretty basic misunderstanding of what the Roche limit is. You are listing the two cases above as if they are different; as if "the net gravity experienced by a point particle . .is shown to be zero" is somehow different from the Roche limit. However, it is not. From Wikipedia which seems reasonably accurate on this topic:
"The Roche limit for a rigid spherical satellite is the distance,

, from the primary at which the gravitational force on a test mass at the surface of the object is exactly equal to the tidal force pulling the mass away from the object." That is almost precisely your definition above. Hence if what you describe happens, then the planet is at the Roche limit (which may well be within Jupiter's atmosphere.)

 

[origin]

However the calculation of the net gravity experienced by a point particle when Mars is about 185000 km from Jupiter center is easily shown to be zero.

So show it.

This causes mass transfer.

Why would this cause a circular area of mass transfer and at the same time cause a mass transfer in the form of a canyon?

The primary cause being volcanism triggered by unbalanced pressure. Nothing is holding the magma down anymore.

If there was no gravity or very low gravity the magma would not rise due to a lack of buoyancy so there should be less volcanic activity not more in low or no gravity situations.

You have given absolutely no compelling evidence to support your claim.

By the way do you have any of the names of the 'many planetary scientist' that helped you with your 'theory'? I assume you do not and that you just tossed in that line to give your conjecture some credibility, but I thought I would ask anyway because, if true, it would be interesting to discuss this with them.