Everything About Telescopes

Calculate Magnification
(Known Focal Lengths)

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You said focal length of objective is 1270 millimeters and
focal length of eyepiece is 13 millimeters.

A telescope of 50.00 inches in focal length is equivalent to 1270 millimeters.

Magnification for a telescope of that focal
length used with that eyepiece is 97.69 x.

This is for my telescope. I can see a Ice cap and a large surface feature with no filter. It may just be your location.

 

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Check to make sure your mirrors are properly alligned and CLEAN.

My little Spaceprobe 3" just with the 10mm eyepiece can find the southern polar cap, and that large surface feature Tristan mentioned. I am under the very distinct impression that dark grove is the Mariner Canyon. It's definetly not that the telescope itself isn't up to the job- mine has only a third the light grasp yours has and I have the same 10mm Kellner eyepiece you do. At only 70x I can see it fine.

I can find all this in the inner city of San Antonio TX, and my home is straddled by two highways within a mile both North and South of me. Light pollution is bad, but obviously Mars is so close and bright that right now this is not in any way an issue. I am very condifent that the issue is more likely that your Spaceprobe 130's optics aren't quite clean and / or alligned properly.

 

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okay thanks.

I don't have a good veiw of mars from my comp, but how much longer is it going to be out?

Oh, and mars was near the moon about a week ago right?

 

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Mars

Mars should be up in the sky for quite sometime yet. It will be rising at the same time the sun sets in a couple of days, and then proceed to rise earlier and earlier each night. So, you'll still be able to see it but it will slowly make its way acrossed the sky until it will be too close to the sun to see it anymore (but that wont happen until middle of next year). It may be visible for quite a long time yet, but it will rapidly get dimmer and dimmer.
I would say at least a couple of months of easy viewing. By the middle of January next year, Mars and Venus will be almost exactly the same distance from us (1.2AU), and Mars will be almost directly overhead when the sun sets, and Venus should be quite high above the horizon also and shining VERY brilliantly (about 5 times brighter than Mars will be getting). So really, there is never a dull moment in our sky!

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Cheers

PS And yes, Mars and the Moon were close by a couple of nights ago. That was actually quite a beautiful sight, I had to stop and just stare at it a few times while I was out.

 

Here in the UK Mars rises with the dusk and, weather permitting, is very clear and bright. It disappears by 0400hrs

 

Red Devil,
How high does Mars get above the Horizon by you? I live in Milwaukee,Wisconsin, which is around 45-ish degree latitude. If my memory serves me correctly, the UK is a bit higher than that?

CJ

 

At a very rough guess I would say, at its zenith, about 60 degrees off the horizon. Last night I was looking at Mars through the front doorway of where I was working, a few sodium lights around, nothing too bright, and I was looking up at Mars, it was very clear and very "red". About 4 nights ago the moon was very close it it and still it was not diminished. I am not sure what latitude I am on, might be worth finding out, but I guess at about 30???

 

In my spaceprobe (900mm focal lenghth), using the 10mm eyepiece tehy gave for a 90x veiwing, how big should mars look.

And about the colimation, I had pretty good vewis of the moon. I just checked it, and I think it's okay, but the directions are funny. They tell you to use the colimation cap, and then look to see if your eye is centered, but you can't see your eye with the cap in =P

Also, when I was trying to veiw mars, when the scope was really out of focus, I could see the crosshairs of the bars in the opening of the scope, and when I moved my hand in front of the scope, I could see taht. Is that normal to see?

 

I just got a 3.1" refractor (celestron) earlier this week. I have managed one outing so far to a dark hill, got some nice views of Mars, saw the polar icecap, but it was a bit low and hazy for anything more, looked kinda pale white.
The other night set it up in the garden, got some great views of the moon. Amazing seeing the craters near the shadow, may have to get a moon filter.

My next purchase may be a barlow or more lenses, any suggestions anyone?

 

Telescope Accessories

I own a Celestron 3.1" refractor myself, nice little scope. If my memory serves me correct, those come with a 20mm and a 10mm Plossl eyepiece? Definately get yourself a moon filter, it can be blindingly difficult to look at without one. I would go for a barlow lens for your next purchase, or a short focal length eyepiece (6mm range). Just make sure you have a decent mount for it, if your using a regular photo tripod with it, its very difficult to use it at magnifications higher than about 80x. Also, I found a Number 12 yellow filter really makes Mars's features stand out if your interested in that.

Cheers

 

I think Mars is about 25 arc seconds in diameter right now?? Somebody can correct me if Im wrong, but if your at 90x, then it should be 37.5 arc minutes in your eyepiece, which is a little bit bigger than what a full moon looks like with the naked eye.

Cheers

 

Tx, my mount seems okay, steady enough. I am looking to buy items that will serve me well, i will def be getting a larger scope in the future. Barlow an moon filter seem to be my next buys.

Btw, as a bit of a newbie looking at the skies, i have to say, it is amazing, just pointing my small scope at a bare patch of the sky reveals countess stars, i think i am in the intitial stages of addiction. Camera, photos are the future, for me just looking at the moon is scintilating!


PJ happy as a pig in ****

 

Hi, I went out again tonight with the same result. While veiweing mars, it was bigger than a pinhead, but not much. It just looked like a big (or not so big) glob of yellow light.

I don't think the allignment is screwed up, as terrestrail objects look fine. I could easily see the boards of a house that was at least a mile away.

Also, when the scope is out of focus (on light), I see the crosshairs of the opening of the scope, and when waving my hand in front of the scope I can see my hand moving. Is this normal?

 

As is always the case here in the UK; when there is something to see, the cloud takes over! Just before Mars reached its nearest point I did get a few glimpses, naked eye stuff, very bright and very red!

 

Out of Focus

Howeman, it is normal to see the secondary mirror assembly when you have your scope out of focus, do not worry about that. Mars is a very small planet, so don't expect it to fill up your entire eyepiece. I can make out the polar ice caps and some dark surface features easily with my small 80mm f/5 at 80x. Sometimes it's helpful to use some color filters, (ei #12 Yellow) as Mars is quite a bright object and the filters can help enhance the contrast of surface features. Also when you are looking at Mars, be sure the air isn't too humid and that Mars is at least 30 degree's above the Horizon, any lower and you are really looking through alot of air and the level of detail can be greatly reduced. What magnification are you using to look at Mars? Also, your eye can compensate for slight misfocused images, but the best way to see detail is to have your eye in a relaxed state (your lens isn't being strained to focus). So take time to get the focus as perfect as you can on the telescope, so your eye doesn't have to. Sometimes you just have to be patient and detail starts to pop out at you as you look. And if you just can't get a good glimpse of Mars no matter what you do, just get up early and take a look at Saturn as it graces our early morning sky, I garauntee that will look awesome in your scope.

Cheers!

 

Mars sure has been bright! I had to apply my polarizing filter in order to see surface detail last night, at around 20% blockage. Only then did the ice caps and Mariner Canyon become visible again

 

Well, Mars should be red correct? It was yellow in my veiwing. I was using a 90x multiplication. Mars was more than 30 degrees above the horizon.

 

Has been clouded here mostly so no Mars for me

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On the good side however I've managed to meet a few people in my area who are interrested in star watching and have telescopes, we will go out soon to watch the sky

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NASA today announced a major milestone in the development of the James Webb Space Telescope (JWST), the selection of a beryllium-based mirror technology for the telescope's 6.5-meter primary mirror. The JWST prime contractor, Northrop Grumman, Redondo Beach, Calif., recommended to NASA the mirror technology, supplied by Ball Aerospace & Technologies Corporation, Boulder, Colo., be selected for the JWST primary mirror.

 

JWST

That telescope is going to be incredible, consider that the Hubble mirror diameter is "only" 2.4m, and look at what it has accomplished with that. This JWST is going to have 7 times the light gathering ability of Hubble.. WHEW! I can only image what new discovery's this scope is going to bring. Too bad we all are going to be in suspense for quite a few more years before it gets put in orbit. But in the meantime, we now have that new STIRF telescope they just lauched, that should be able to peer through all the dust in our universe and see whats been hidden. Keep up occupied until JWST see's first light.

CJ