I have been looking at this page ( http://www.newton.dep.anl.gov/askasci/ast99/ast99159.htm ) but find myself dissatisfied. First, an explanation like:
“For an orbit far away from the moon our satellite would encounter the gravity of the earth and that would alter the orbit and make a stationary orbit unlikely. Because of the earth’s presence such an orbit is n ot possible”
is simply opinion, not demonstrated fact or convincing calculation.
Second, my verbal interpretation and math competency are completely inadequate for the following:
“If it were, you could use the value of the radius for earth and multiply it by the one-third power of the ratio of the moon to the earth masses and multiply by the two -thirds power of the number 28. That should give the value without the prese nce of the earth.”
So I put to you the question: Are lunastationary/lunasynchronous (shortened to “Luna_S”) orbits possible?
To some extent the answer is “Yes”. The 5 Lagrange points of the Earth-Moon system are Luna_S, and the Earth itself is Luna_S. Saying these things are in “lunar orbits” may not be the most accurate way to describe the situation, but from the surface of the moon all six of these spots are somewhat stable and somewhat unmoving, and are in Luna_S orbits sufficient to satisfy me.
I wonder about other orbits, though. The Earth has “Geo_S” orbits at about 35,800 kilometers; to what extent can the moon have a similar ring of Luna_S orbits? My best pass at figuring this (assuming no Earth in the calculations) is that the ring would be around 88,000 km above the moon’s equator.
Is the Newton site linked to above right in saying that such orbits are impossible? Because of the presence of the Earth I imagine the possible locations would not form a circular ring, and might not form a complete ring at all. But I do not see why stable Luna_S points (hereafter to be known as “Blade points” ( )) cannot exist, say, 88,000 km preceding or trailing the moon in its orbit (like the L4 and L5 spots, but closer to the moon).
(If lunar satellite in a Blade point were big or bright enough to be visible from Earth, it would appear to be unmoving relative to the moon; that would be an interesting thing to see.)
So anyone want to help figure this out? Can there be “real” Luna_S orbits?