It occurred to me recently that the Equatorial telescope mount will work not only on Earth, but on Mars as well. Mars' inclination is only a couple of degrees more than earth, and it's day only a tad longer than ours. Any earthly EQ mount could be polar-aligned on Mars, and the correct tracking rate easily adjusted by either a drive corrector for synchronous motors, or with software for stepper motors. No gearing or motor changes needed at all. In case you are interested, here is a link to a chart showing the north circumpolar sky for Mars: http://www.eknent.com/etc/mars_np.png Mars has no significant pole star in the northern sky. I suspect that even if we could determine rotation rate and axial tilt for exo-planets, we would probably have to search through millions before finding another one that would allow a stock Earth equatorial mount to function, right from the box (temperature and atmospheric details aside). What an incredible coincidence that we have two such planets right here in the solar system. And they have adjacent orbits!