Recent content by LesRhorer

Do the math, folks. The Moon travels a path apparently around the Earth with an orbital amplitude of roughly 800,000 Km. In reality, the Moon travels around the Sun, and the Earth has a significant, but smaller influence on the Moon. The Sun's gravitational influence on the Moon is nearly...

In what direction? In order to know the answer one must know the velocity vector of the asteroid compared to the orbital velocity of the Earth. It looks to me like the simulation assumes the earth is not in orbit around the Sun. In this case, it is a simple 2 body problem, and the answer...

I agree, although it s really merely a semantic issue, and not terribly important as long as everyone in a discussion uses the same definitions. To be sure, if both energy and momentum are conserved, the interaction is elastic. I think most people would expect a collision to involve mechanical...

'Not much. The most efficient transfer occurs when the orbit is a hyperbola. Starting out any faster wastes fuel, although of course it may be necessary depending on the alignment of the planets. Nothing is perfect, after all I think you mean "velocity" :cool: The shape of an orbit which...

Such as? The point of a gravity assist is to enable a spacecraft to achieve very high velocities without using much fuel. Attempting to do this in a 2 body system results in no increase in velocity at all.

I fully recognize the difference. Not quite.I recognize they are two different things. They have to be, of course, since the kinetic energy is not proportional to the velocity. Of course. I never said differently. My point (and its is not the main one) is the only way to effect a change of...

False. This is not an effect of the tidal potential. it is an effect of the fact (and magnitude) the system has a angular momentum Again, that is false. The path is not symmetrical to the CoM of the two bodies. Inbound the speed is close to escape velocity of the planet. Outbound it can...

Perfectly correct, of course. The point is the total kinetic energy of the system remains constant. If we fly a jet over the two balls, the relative energy of the system in the FoR of the jet is HUGE, but at the moment of the collision the energy of the two ball system WRT the jet does not...

Actually, for the slingshot effect, we stipulate it starts right at or rather near zero, an infinite distance away. Such an orbit is one right at escape velocity.Any faster and it is not quite a hyperbola, and the craft will never return. Any slower, and it isn't quite a hyperbola, either, but...

No, it can't. No matter what, an interaction between two solid bodies can never result in the system gaining energy. That would be an absolute violation of conservation of both energy and momentum. It also cannot ever lose momentum, and can only "lose" energy if something internal to the...

True. This would probably have to be some vehicle coming in from deep space. As you very clearly are aware, the required parameters for a gravity assist are rather narrow. Instituting an actual hyperbolic orbit around a neutron star from only a few million Km away would be tricky, indeed...

I did respond. Untrue. Although I mentioned it previously, I will clarify again right now.The only reference from any knowledgeable sources I have ever seen is the method used by NASA for Voyager, Casini, etc. to increase the speed of a vehicle relative to some very massive body by the amount...

Thanks! I always enjoy spawning a spirited, yet polite, debate. True, mostly. It is very easy to accidentally make an error in physics that causes one to apply the math incorrectly and wind up with an answer that is physically incorrect. That is specious for a couple of reasons. First of...

The math surrounding the gravity assist requires the small object to be optimally traveling at escape velocity for the primary. It also needs to be traveling at a speed similar to the orbital velocity of the primary. One can see why this needs to be the case, because the gravitational...

Nope, not even a little. Not even close. The orbital motion of the barycenter of the planet / asteroid system is crucial, especially since the net effect of the planet's gravity on the asteroid's speed is dead zero. Once again, the planet's effect on the speed of the asteroid at any given...