Horace Heffner wrote: > Just to complete my thought. > > > On Jul 28, 2009, at 5:02 PM, OrionWorks wrote: > > >> "We should go boldly where man has not gone before – fly by the >> comets, visit asteroids, visit the moon of Mars. There’s a monolith >> there. A very unusual structure on this little potato shaped object >> that goes around Mars once in seven hours. When people find out about >> that, they’re going to say "Who put that there?" Well, the universe >> put it there. If you choose, God put it there." > > Mars has *two* moons, Phobos and Deimos. Strange he would make that > mistake. > > Since the larger, Phobos, has an orbital period of 7.66 hours, he must > be talking about that one. It certainly is small, diameter 22.2 km. > Not much energy required to adjust the orbit of a very low flying low > speed robotic survey satellite so as to photograph every centimeter of > it in 3D from multiple angles, and then land for close inspection. > > See: > > http://en.wikipedia.org/wiki/Moons_of_Mars > > Phobos has a mass of 1.08 x 10^16 kg, and radius of 11.1 km. At surface > grazing altitude, a robot satellite would have a velocity v given by: > > v = ((G M)/r)^0.5 = 8.06 m/s > > That's about 18 miles per hour, bicycling speed. Orbital period P is: > > P = (2 Pi r)/v = 8653 seconds > > That's about 10 orbits per earth day. Using laser ranging it should be > possible to develop precise surface contours and identify surface > gravitational variations. Then close flybys and photography of any > surface feature can be made in 3D. Using solar power and ion rockets, > orbits can be adjusted for close flyby to any location. Communications > can be handled via link with existing Mars communications relay > facilities. As these kinds of missions go, this one could be > comparatively cheap. The problem is actually knowing there is something > there to make the mission worthwhile. > > And what if there *is* a monolith there. How to communicate with it?
"Monolith: n : a single great stone (often in the form of a column or obelisk)" Outside of certain stories by Clarke, "communicating with" a monolith is not just difficult -- it's impossible. Rocks are notoriously uncommunicative. Note that, at least in the quoted text I've seen, Aldrin didn't say anything to imply that the "monolith" was more than an unusually shaped hunk of rock, nor did he say anything which implies it's more than a visual curiosity. Certainly he said nothing which would imply attempts at communicating with the monolith would be more productive than attempts at communicating with, say, a swivel chair.
