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Resolving Mars Surface Features


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I have an 8" f/5.9 reflector. I eagerly went out last night to test my new 6 mm eyepiece. It was my understanding that with the magnification it provides I'd be able to resolve some large surface features like polar caps or shadows from mountains or *something*. All I saw was a white blob, albeit larger than the blob I saw with my 25 mm ep.

Yes, it was in focus (stars were pinpoints). No conditions weren't ideal, but I was really hoping for something to be excited by.

Are my expectations too high?

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Hi Beltalowda,

I have seen features such as those with a 4.25" f8 reflector at opposition some years back. One possibility is that with your 8" the image might be too bright. Maybe you can try to use a colored filter to reduce the brightness and increase contrast to some degree. My guess is a dark red or orange filter will bring out more detail.

Best! 

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Mars has been a real challenge this opposition, and unfortunately is now heading away from us so will only get more difficult. A dust storm over much of the planet hid, or at least muted most of the main features. The most I’ve seen this year has been the polar cap and some fairly indistinct dark markings, that was with a 4” refractor.

Next opposition should also be quite good, with Mars higher in the sky, although a little further away than this time around.

Coloured filters can help to cut the glare, or more expensively a Neodymium filter also works well whilst keeping a fairly neutral tone. Cooling and collimation of the scope are too other key elements to get right in order to see any detail.

Mars is an enigma really, astonishing on good nights and very very dull on others. I think we have all been there in terms of observing a blank white/orange disk, so can share your pain!

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We had a look last week and couldn't see much.

But, yes, with an 8" 'scope we have seen the polar cap and some dark markings.

As Stu says, not sure there's much happening this time around.

Even on a bad night though, it's still most definitely a planet you are seeing from you back garden and not a star! ;)

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If it's any consolation, I have been viewing Mars this apparition with telescopes of several types ranging from 4" to 30" and have not done any better. Mars has been too low to be able to use much magnification due to wind farm turbulence locally.    ?

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I’ve been viewing it in my 90mm f9 refractor fairly religiously over the last few months - made out the northern cap clearly once and the rest of the time it’s been a fairly mediocre experience. I think it’s  been the same for everyone. 

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I have always found the telescopic view of Mars to be somewhat uninspiring. At the previous opposition I only had my 127mm Mak and struggled to make out any surface detail at all. Acquiring a 203mm Newtonian OTA did not give the improvement in planetary views that I hoped for.

At the 2018 oppositions of Jupiter, Saturn and Mars I have concentrated on imaging the planets, which for me shows more detail than I can see through an eyepiece. If you look in the Planetary Imaging section you can see what sort of detail can be captured under the right conditions.

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25 minutes ago, Beltalowda said:

Thanks for all the replies. The proximity of Mars is what finally pushed me over the edge of buying this scope, so that is partly what's fueling the disappointment. But it's good to know I'm not alone.

The scope and eyepiece are a good combination and will show you plenty of other targets, plus the planets will be back again so nothing is lost. Try some globular clusters, they should look pretty good.

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Hello everyone! Sounds like I'm not the only one still struggling to see many details. I have a Heritage 130P on a Porta II and using Baader Classic Orthos (10 and 6mm) with their 1.3/2.25x barlow. I think my suburban early-evening seeing in North Bristol has been fairly bad as its hard to even achieve really decent focus (especially with the plastic helical-type focusser)...

Any advice? I've only had the Heritage a matter of months but already thinking about adding a scope thats better for lunar and planetary performance...

Cheers all,

Rob

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With Mars what you see depends on where the planet is in it's rotation.

You also need to ensure good collimation and cool down.

Try to plan observing when Syrtis Major is face on - even then at the moment it will appear only as a subtle darkening on the planet surface.

The phase is now fairly obvious and you may just glimpse the polar cap - which will only look like an area that is a bit brighter than the surface.

I have only had one good viewing session this time around through a 5" Refractor when the seeing was unusually good given the low altitude of Mars.

This image by @orion25 shows how it almost looked......

 

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@beka@Stu, and @dweller25 all make great points. A large aperture scope will make the image too bright. My 180 Mak shows an almost white disc with a few soft shadows; when I image with it, I always have to turn down the brightness on the camera to see any detail. My 127mm Mak fares a bit better, but a Mars filter and, perhaps, a polarising filter will cut the glare and reveal more detail. What features are actually visible at the time of observation is also a consideration. Sometimes, albedo features may not be as prominent. And, of course, there was the global dust storm that, for a while, obliterated much detail. The low altitude doesn't help though it's rising now. But more detail is able to be seen now since the dust storm has settled, so you can try viewing on a night with good seeing when albedo features such as Syrtis Major is visible, and use a Mars filter like the Celestron or Orion, or maybe a polariser to cut the glare.

Best wishes and clear skies!

Reggie

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I looked at Mars just last friday nov 9 with a 10" dob. I must say I was pleasant suprised, I finally saw some structure and phase on the red planet. seems like the dust has settled down. Maybe try a little bit less magnification. I had the best result with my 8mm. 

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Add into the above (good posts and advice ) the fact that viewing changes by the hour.

During a previous Mars approach a club about 25 miles away was holding a public evening to view Mars in their 12" reflector.

Before setting out, I took a quick look through my MN78 (which I know is an excellent scope for this sort of target) and saw a featureless blob.
I conclude that my trip out was not going to offer anything much of Mars. But I could have a chat with club members and look at their big scope.

At the club I was really pleased with the Mars views. There was quite a bit of detail. In fact I began to wonder if there was something wrong with my MN78.
Was I comparing it to my previous poorer scopes? Had the optics degraded? Was it out of collimation? We have all been there questioning our scopes.

Returning home a couple of hours later the MN78 gave fantastic Mars views with detail.
As good as the club 12" reflector - well I would say that!
All done by waiting a few hours.

Later the view degraded in a short time. But that was condensation on the corrector plate.

Good views are never guaranteed.

David.

 

 

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