Jovian Moons

[PSALM19.1 (Shaun)]

Is it possible to see other Jovian moons besides the Galilaen Moons with an 8" Dob?

[Allan]

Even the largest telescopes in amateur hands can only see the 4 Galilean moons. The 5th largest moon is very faint and only about 200km across.

[barx1963 (Malcolm)]

The fifth largest moon Amalthea was discovered by Barnard in 1896 using the 36" Lick refractor and was the last natural satellite in the solar system to be discovered by visual means and the first Jovian moon discovered since Galileo
Theoretically a very large amateur scope could pick it up as it has an apparent magnitude of 14.1, but it orbits very close to Jupiter itself making it very hard to pick out.

Malcolm

[barx1963 (Malcolm)]

Hunting small moons is much easier with Saturn. The 5 largest are all easy to get (Titan, Rhea, Dione, Tethys and Iapetus while the much smaller Enceladus (500km diameter and apparent mag 11.7) is possible with a 12" (I know as I have done it) and certainly smaller scopes when it is a reasonable distance from Saturn and the even smaller Mimas (diameter approx 400km and apparent mag 12.9) is much harder as it is dimmer and orbits much closer.

Malcolm

[rustigsmed (Russell)]

tonight will be worth checking out the double shadows of Europa and Callisto crossing the jovian disc.

[AG Hybrid (Adrian)]

Originally Posted by barx1963

Hunting small moons is much easier with Saturn. The 5 largest are all easy to get (Titan, Rhea, Dione, Tethys and Iapetus while the much smaller Enceladus (500km diameter and apparent mag 11.7) is possible with a 12" (I know as I have done it) and certainly smaller scopes when it is a reasonable distance from Saturn and the even smaller Mimas (diameter approx 400km and apparent mag 12.9) is much harder as it is dimmer and orbits much closer.

Malcolm

Hyperion. Mag 15.3. Must...find...it....

I've never seen it. I've tried for it probably 20+ times. 12" might just not be big enough.

I have been able to get Triton around Neptune though. Which is a huge buzz. Its ~mag 14. That's a good one to go for!

[PSALM19.1 (Shaun)]

Yes, have caught the faintest of glimpses of Triton once....

Also, poses a question, why can you see small moons around Saturn which is further away than Jupiter and it's small moons?

[Camelopardalis (Dunk)]

Glare. Jupiter is relatively bright so makes it harder to discern fainter objects in the FOV.

[OzStarGazer]

This happened to me too tonight... More than 4 even show in the photos I have taken. They really look like 5 even in the photos. But I guess it is just glare.

[Camelopardalis (Dunk)]

Triton was a high for sure...never would have got that without Adrian's help, but it was there in my C11 too.

[Camelopardalis (Dunk)]

Another point about the moons of Jupiter...if your scope has sufficient resolution they're no longer points of light, their bigger than that...with my first scope I used to use them to focus my scope

[OzStarGazer]

They look like fat stars.

[Camelopardalis (Dunk)]

[barx1963 (Malcolm)]

Originally Posted by OzStarGazer

This happened to me too tonight... More than 4 even show in the photos I have taken. They really look like 5 even in the photos. But I guess it is just glare.

Any other points of light beyond the 4 Galilean moons will be background stars.

Malcolm

[OzStarGazer]

It is an interesting effect when they are so close to Jupiter! Searching on the net, the question has been raised before because sometimes they look like Jovian moons (same dimensions as the other moons) and are so prominent.
Anyway, I checked in Starry Night. There were indeed a few bright stars very close to Jupiter just when I was watching. I actually saw 5 + a 6th one which was less bright.

[smithcorp (Brian)]

Getting to see the Jovian moons was a huge highlight for my daughters on Saturday night - great views through the binos and telescope.

[Suzy]

Shaun, Europa will be making a gorgeous shadow transit across Jupiter on Valentine's Day (at night). There's probably going to be a lot of broken hearts that night when Valentines get ditched for a night of observing. In my case, the best pressie I could give would be to be outside observing so he can have peace and quiet .