Be gentle with me Brandon - but if two objects leave the same point at three quarters of the speed of light in opposite directions are they travelling at 1.5 times the speed of light away from each other? (high school physics and first year uni only - and the odd Asimov non-fiction book)
All this talk of 'planet of origin' is freaking me out - do you mean 'frame of reference'? Sorry it just sounds like I could break the lays of physics if I left a planet other than my own.
General relativity has a geometric and a field interpretation. If angular momentum conservation is invoked in the geometric interpretation to explain experiments, the causality principle is violated. Meanwhile, the field interpretation avoids this problem by allowing faster-than-light propagation in forward time. Lightspeed is not a universal speed limit.
Now that we know that Lorentzian relativity is experimentally viable  and allows faster-than-light (ftl) propagation in forward time , ftl propagation is no longer forbidden in physics, and ftl force carriers are the most reasonable interpretation of the equations. I expect that no one would ever have thought otherwise if they had not mistakenly believed that ftl propagation was forbidden in physics.
A mechanical answer.
Two objects receeding from each other each travelling at 75% of the speed of light "c" would not be able to "observe" each other for the simple mechanical reason that the light between one and the other would be "red shifted" towards infinity. The energy level of the wave to the observer would be too low to be able to convey any information although an observer at the midpoint would be able to see both objects. If you define a universe as everything inside a volume contained within a sphere emaniating from a "big bang" and delinated by a microwave "horizon" it becomes rather obvious that nothing within the observable universe can exceed the speed of light "relative to an Earthbound observer.
Consequently we can observe nothing in the universe travelling faster than "c". This is merely a commentary on the physical nature of light and our conception of the universe and will have little to do with the nature of the universe.
Catch up with the times dude
But then that is the Great Lure of Science
in understanding what really is
Electromagnetic radiation does not travel faster than C and no particle which we have observed travels that fast.
Nonetheless gravity propagates instantaneously to within our ability to measure it and there is sound reason to believe that what we have been calling the basic atomic particles for the last hundred years have their own orbital systems and sub particles and that the computed necessary speed of one of those sub electron particles would be vastly greater than C.
A theoretical faster than light particle is called a tachyon: It would behave in the opposite way to our universe in terms of energy: e.g. the harder you pushed it : the more it would stay still: Isaac Asimov did a good explanation of this .
Tachyons could have been created before the laws of physics were invented: or they could have invented themselves: science should be about thinking how the impossible could be achieved:
Feynman preserves the force and motion concepts with their classical meanings, and comments: "It is one of the peculiar aspects of the theory of gravitation, that it has both a field interpretation and a geometrical interpretation. ... the fact is that a spin-two field has this geometrical interpretation: this is not something readily explainable - it is just marvelous. The geometrical interpretation is not really necessary or essential to physics."