Monday, January 16, 2006

tidal lock

Bluemama asked if these moons have the ability to change their ratios. The answer is yes and no. The moons seem not to have the ability to tidally lock themselves to their primary, because this tidal lock is affected by the primary upon the moon – the greater to the smaller – although the moon does tend to affect the planet. The moons themselves though tend to affect the orbits of one another and arrive at the ratio needed to keep stability.
Tidal lock is a phenomenon that occurs when a satellite orbits closely enough with its primary. The gravitational pull upon the satellite causes it to bulge slightly. The process of this bulging though is slow enough that it occurs just after the point being pulled upon has passed. The bulge itself gets a tug backward toward where it was affected, in the direction opposite its orbit, which tends to slow it down slightly. This delayed reaction bulge effect and the opposite pull on the bulge, and the slowing affect, over time tends to cause the tidal lock as the orbit and rotation synchronize.
So, with the metaphor in your mind, it is only through a close orbit, a constant tug, a slow response from the satellite, a persevering pull on the slow-reacting satellite, over a great amount of time, that the satellite is brought into tidal lock with the primary. Probably safe to say that it takes a lifetime.