I have read that its possible to see the furtherest out moons from a dark steady sky using a knitting needle end as a mask ( block ) on Jupiter its self , but it would be very hard .
You need a blackened tube 30mm in diameter about 100mm long with the needle poking thru one side to 1/2 way about 25mm from the eye end and mounted on an EQ mount with a solid support to keep your head very , very still .
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I think I will just use my scope
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Dennis DeCico of S&T mag did it once years ago , he has telescope eyes they say
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Brian.