I have a question! Mars' moon...

In message , Jeff Root
writes
Matthew F Funke replied to Volker Hetzer:

why are [planets] not tide locked with the sun?

[I disliked the wording of Volker's question so much that I
felt compelled to modify it. --jr]

Well, Mercury is locked in a sort of resonance with the Sun --
kind of a simple tidal locking. As far as the rest is concerned,
remember that tidal locking becomes much more pronounced as the
bodies in question get closer to each other (tides go down with
the *cube* of distance, not just the *square* as gravity does) and
as they get close to each other in mass. The planets are *much*
smaller than the Sun.

Similarity of mass can't be a factor. Gravity-gradient
stabilization has been used on many low Earth orbit satellites,
such as some of the US Navy Transit satellites in the 1960s,
the GEOS satellites in the 60s and 70s, and Geosat in 1985.

Isn't the important factor the gradient across the object? As you say,
it's actually called gravity-gradient stabilisation when it's applied to
artificial satellites (it's also more syllables than "tidal locking", so
it sounds cool).
--
"Forty millions of miles it was from us, more than forty millions of miles of
void"