observing jupiter

[foffof]

What is the minimal aperture and magnification to see the the great red spot in jupiter? The same question about moon's transit?

[inspectapart]

This depends on several things. Seeing conditions as well as quality and size of the scope and eyepieces used will play a part in what you will see at any given time.. You may be able to make out some markings on Jupiter at as little as 40- 50x magnification, if the seeing and position of the planet are good. But to get a reasonable view of the ellusive red spot and transits of moons, I personally like to use an ep that gives me around 100x to 150x magnification in my 4" refractor. And even higher magnification can be used, as long as the seeing and position of the planet are good enough to keep the image clear. It`s trial and error really. You`ll soon get know what to expect to see at the eyepiece with practice.

Bob

[John]

As per my reply under your thread on Saturn's features really. Depending on viewing conditions, observer experience etc, etc I reckon 80mm is about the minimum but it can be a tough spot at that aperture. The GRS is pretty pale at the moment which does not help.

I find the GRS much easier to spot with a 120mm refractor. Moon transits similarly although they are a bit easier to see than the GRS usually as the contrast between Jupiters cloud tops and the moons shadow is very distinct. It's harder to see the disk of the moon itself in transit though.