Fairly basic question

hi all... me again... jus a quick question... went out last night (first and last clear one for a while i believe!!), wit 9" SCT to have quick look at jupiter.. what i saw was following.....

SMALL featureless white disc, and its moons as fine pinpricks of light.
I could only BARELY make out VERY faint bands (and even this only with offset peripheral vision). Absolutely no way would i be able to see Great Red Spot, for example, if it was in position. I used all lenses and barlow but all this produced was a bigger, equally featureless disc.

I realise that conditions were FAR from perfect,.... still a bit of twilight, hazy atmosphere, and planet fairly low (maybe 10 to 15 degrees above horizon).

Should I expect more, or was it just seeing conditions.?

Maybe long exposure photography only way to bring out features??

I will be able to compare and view and chat other folks when local club in galway starts meeting again but for now I would appreciate your opinions.

Hope im not soundin too dopey!! :oops:

thanks folks


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SMALL featureless white disc, and its moons as fine pinpricks of light.
I could only BARELY make out VERY faint bands (and even this only with offset peripheral vision). Absolutely no way would i be able to see Great Red Spot, for example, if it was in position. I used all lenses and barlow but all this produced was a bigger, equally featureless disc.

Don't worry I've a 10" Dob and that was the best I got also, I though I could see the hint of the rings with averted viewing but I'm not really sure.

I realise that conditions were FAR from perfect,.... still a bit of twilight, hazy atmosphere, and planet fairly low (maybe 10 to 15 degrees above horizon).

Should I expect more, or was it just seeing conditions.?

Maybe long exposure photography only way to bring out features??

From my understanding (I'm pretty new to this also) your eye simply can't take in enough light, even with the telescope to enable you to see fine details at these distances. However as you've correctly suggested film is much better at capturing the light and using this to build up an image over time. I'm sure you've seen people on the site talking about thing like 4 exposures at 60 secs each. What they're saying is that they took a lot of shots and combined them to make a single image with lots of light information.

Hope im not soundin too dopey!! :oops:

Actually I thought the same also until someone put me right, I thought I'd see in real time views near to the images captured by Hubble with a large scope, unfortunately not. But amazing never the less :shock:

Don't be afraid to ask questions. You will see Jupiter a lot better than this. The atmospherics have a MAJOR part to play. Although I wasn;t out myself last night it does sound like the 'seeing' was pretty bad. The moons will never be more than pin pricks in a scope. You will see the red spot, in time when the atmospherics are right. The trick is to patiently watch until the atmosphere steadies down for a second (or even less) and allows you a really good view.

I might suggest that as a newcomer your focus might not have been bang on either. Practice this it does take a bit of work to get the technique right.

As far as the eyepieces go, the smaller the number the higher the magnification. Star with something around 25mm and work your way up the magnifications. This will allow you to see when you have reached a limit that the atmosphere wont let you pasr.

I have seen very fine detail on the planets (incl Jupiter) with a C9.25 SCT so I have no doubt your scope is well up to it.

Patience is really the key.

hi maygrey

This is normal, there are a few factors which can make jupiter appear like this. as you say jupiter is low down so you are looking through a lot of mucky atmosphere.

If the atmosphere is not steady it is hard to pick out detail, especially when jupiter is so low down.

If your scope is out of alignment (collimation) it can cause blurry images,but I wouldn't worry about this just yet. The fact that jupiter is low down and bad atmospheric conditions can ruin your viewing.

Also, a lot of the detail is subtle and the more time you spend at the eyepiece the better you will be able to spot this detail. Keep at it and when you get a good night with a steady atmosphere you will be surprised at the amount of detail you can see.

If conditions are bad,often you are better with lower powered views.

I have an 8 inch and when conditions are good it is easy to see quite a bit of detail,including banding, dark swirls (festoons) and the red spot although this can appear as a paler spot in the dark bands.

In the meantime check out jupiter's 4 brightest moons, they should be strung out on either side of the planet and they change position from night to night and some over the course of an hour or so.

somtimes a few of these moons might be behind or infront of the planet, so you may see 2-3 moons. If the moon Io is passing in front of the planet you should be able to watch its shadow crossing jupiters disc and this is pretty neat. you will get times for this on the internet or in most astronomy mags.

Hi Maygrey.
Don't expect too much from Jupiter right now.
10-15 deg's altitude is not going to show the planet at it's best.

I was in Portugal last month and had an extra 15 deg altitude making it around 30 deg or so and it was still hard to make out detail visualy.
Having said that, that last clear night we had I had a look and was blown away by what I could actually make out.
I could clearly see the major bands and the GRS was very obvious.
This was down to excellent seeing for a brief time.

Imaging the planet 'beats the seeing' sort of, but at the end of the day
you can't beat good conditions.

It also depends on the scope.

Maygray,
You had better luck than I did,Isetup about 800pm and by the time it got dark the clouds and ground fog had moved in, I did'nt even get see anything
Jay