Detail on Ganymede ?

[E621Keith]

Very interesting post. I never thought it would be possible to see disk details in Jovian moons. At the moment, I'd consider myself lucky if seeing allow me to push above 200x. For me trying to see GRS is hard enough already. Recently, thanks to those thin high level clouds, I struggle to get good view even at 100x.

I just looked at some photos of Jupiter taken by Damian Peach with his C14. It looks like a 14" scope does have enough resolving power to see some details in Jupiter's moon. However, I guess you will need have very clear and steady sky, a big, good quality, well collimated scope, and be a very good planetary observer to attempt it.

[chiltonstar]

Some interesting posts on this "elsewhere", where folk have seen detail on Ganymede with much smaller scopes, even 8" - maybe size isn't everything!

Chris

[paul mc c]

I think good optics and seeing are a major factor.

[chiltonstar]

I've simulated what Ganymede would look like (at 1.5 arcsec), starting from a Nasa pic, then blurred to correspond to an airy disk of 0.5 arcsec (seeing plus diffraction limit derived from aperture) and an airy disk of 1.0 arc sec. This would indicate that you might see some albedo if the seeing was excellent and the optics good, even with 8" aperture (as reported on CN).....

Chris

[John]

I've simulated what Ganymede would look like (at 1.5 arcsec), starting from a Nasa pic, then blurred to correspond to an airy disk of 0.5 arcsec (seeing plus diffraction limit derived from aperture) and an airy disk of 1.0 arc sec. This would indicate that you might see some albedo if the seeing was excellent and the optics good, even with 8" aperture (as reported on CN).....

Chris

Very interesting Chris - there is hope yet then

[paul mc c]

This sounds like a challenge...... .