Rotation period for fictional ganymede

[ffutures]

According to Stanley Weinbaum (or rather Helen Weinbaum, who wrote most of Tidal Moon after he died) Ganymede has high tides caused by Jupiter's gravity, with peak tides every three months. To me this suggests that Ganymede is rotating just a little faster than it orbits Jupiter, and slowing towards a tidal lock.

My maths is crap, but given that Ganymede's orbital period is 7.16 days, and you would get two high tides per rotation, I'm working this out as a day of about 6.5 earth days. Anyone feel able to work this out properly?

Comments

[lapswood.livejournal.com]

Our mutual friends, pmcray & major_clanger are very good at stuff like this. Try asking via lj direct message if you need more help.