Having trouble seeing details on planets

[Sedna]

I have a Celestron Nexstar 8SE (203 mm) and even under ideal viewing conditions, I'm having trouble viewing details on planets. For example, on August 31, I was observing Mars at a Bortle 2 site, very dry location, high elevation (1,900 m). Someone correct me if I'm wrong, but I believe this is after the dust storm had already cleared up. However, even under high magnification (8 mm eyepiece with Barlow lens), I could not see any detail, just a featureless, bright orange ball.

What, if anything, am I doing wrong? I tried several eyepieces, do I also need a filter? The only thing that seemed to work was the LCD screen of the camera that I then hooked up to my scope. I was viewing Mars live on the LCD screen, and for just a fleeting moment I thought I could see the southern icecap and some black surface features. They then vanished, and I'm still unsure whether it was just my imagination. Anyway, this is a question about visual observation (not the camera), so is there anything I can do to improve? I've also looked at Jupiter and Saturn and they don't seem much better ... Thanks!

[Demonperformer]

500x magnification (assuming a 2x barlow ... 3x would just exacerbate this problem further) is IMO far too high. If you apply too much magnification, the light from the "details" gets spread out over such a large area that it becomes much fainter. You will always see more on a small bright image than a large faint image. [image as in on the retina rather than in a camera]

What are you using to ensure focus is correct? It is best to focus on a star and then go to the planet (or the moons of Jupiter are good). Points of light are easier for getting focussing spot on.

The other thing I would say is that "seeing" (rather than "looking at") is a skill that needs to be developed. Can I suggest that one way to develop your seeing skills is to sketch the moon. I'm not talking about sketches you would be happy to display on the forum (although if your artistic skills stretch that far that would be great), but just pick a bit of the moon and try to accurately depict the sizes and relative positions of the craters. You can then compare your results with a lunar map (Virtual Moon Atlas is a good - and free - one). You will quickly discover that your ability to "see" what is in the eyepiece will improve.

[Pete Presland]

Mars was still being affected by the dust storms at the end of August, although not as bad as earlier in the month. Mars, Saturn and Jupiter, will all show some details in good conditions. Its worth observing for quite long periods to allow your vision to adjust to the view, so getting comfortable is essential. High magnification is not always the answer and can make the view worse at times.

Mars should show some surface detail and a polar cap. Saturn, obviously the rings and sometimes maybe a belt around the disc. Jupiter, you should be able to easily see both equatorial belts, the GRS (great red spot) and 4 moons, assuming one or more are not eclipsed by Jupiter.

 

[mikeDnight]

At its current size, a power of between X170 and X200 would be good for Mars. As well as the dust storm, which has plagued this apparition, you may have been looking at a less detailed region of the planet, as not all aspects have easy to see albedo features. Anoher possibility is that you were magnifying the heat inside your scope, which would just wash out any planetary detail. The seeing can be excellent but the heat within an SCT can take between 1 to 3 hours to dissipate. It's best to keep such scopes cool as they are slow to release their internal heat which is amplified by the secondary mirror.

[John]

Mars is still affected by the dust in it's atmosphere to some extent so details on it are harder to pick out than during "dust free" oppositions.  I think much lower magnifications plus spending some time observing Mars may pay dividends for you. Allowing the scope to cool fully is important as well. Detail on the planets does seem to "come and go" as the seeing conditions fluctuate which is why extended observing helps - you get more chance of picking out the moments of really good seeing.

 

[Knighty2112]

I was out the other night observing Mars at around 200x in my Omni 120mm ‘frac, but sadly the jet stream was playing havoc with the view. I tried to image it too but no joy as it was bouncing around in the camera view too much to get anything good from it. As suggested anything more than 200x will mostly be too much on most nights in the UK, except on some exceptional nights where you might be able to go higher if the jet stream is not causing problems, and the seeing is nice and steady. The highest I have really pushed my C8 SCT (which is basically exactly the same as your 8SE except for the colour basically) is using a 5mm EP which gives just over 400x view, but only on a handful of occasions has the seeing been good enough to see anything usable with it on any of the planets.

[david_taurus83]

I've only managed to view Mars a handful of times this year. The first was an utter failure. Nothing but a bright orange mess. This was at the height of opposition. A few weeks later I tried again with more success. Best I've found was a 5mm eyepiece in my 200P 1000mm so x200. Icecap and some dark features visible, just. I also have a manual filter wheel with some rgb filters in so I also wheel through these to see which gives the best contrast. The blue and green are very good on Jupiter and also improve the view on Mars for me.

[Sedna]

14 hours ago, Demonperformer said:

500x magnification (assuming a 2x barlow ... 3x would just exacerbate this problem further) is IMO far too high. If you apply too much magnification, the light from the "details" gets spread out over such a large area that it becomes much fainter. You will always see more on a small bright image than a large faint image. [image as in on the retina rather than in a camera]

What are you using to ensure focus is correct? It is best to focus on a star and then go to the planet (or the moons of Jupiter are good). Points of light are easier for getting focussing spot on.

The other thing I would say is that "seeing" (rather than "looking at") is a skill that needs to be developed. Can I suggest that one way to develop your seeing skills is to sketch the moon. I'm not talking about sketches you would be happy to display on the forum (although if your artistic skills stretch that far that would be great), but just pick a bit of the moon and try to accurately depict the sizes and relative positions of the craters. You can then compare your results with a lunar map (Virtual Moon Atlas is a good - and free - one). You will quickly discover that your ability to "see" what is in the eyepiece will improve.

Thanks Demonperformer, I just adjust focus manually until it looks sharp. Could be part of my problem, but I doubt that it can explain everything. I see you also replied to my post on focusing the scope in the imaging forum, so you know about the problems I'm having there, but those are mostly for deep sky--planets seem easy to focus.

Will take you up on the moon sketching idea some night ... hopefully I can graduate quickly to Jupiter sketching.

[Sedna]

10 hours ago, david_taurus83 said:

I've only managed to view Mars a handful of times this year. The first was an utter failure. Nothing but a bright orange mess. This was at the height of opposition. A few weeks later I tried again with more success. Best I've found was a 5mm eyepiece in my 200P 1000mm so x200. Icecap and some dark features visible, just. I also have a manual filter wheel with some rgb filters in so I also wheel through these to see which gives the best contrast. The blue and green are very good on Jupiter and also improve the view on Mars for me.

Thanks, I will try some color filters. I think I am just really frustrated that Mars is at opposition and I can't see anything

[Sedna]

11 hours ago, mikeDnight said:

At its current size, a power of between X170 and X200 would be good for Mars. As well as the dust storm, which has plagued this apparition, you may have been looking at a less detailed region of the planet, as not all aspects have easy to see albedo features. Anoher possibility is that you were magnifying the heat inside your scope, which would just wash out any planetary detail. The seeing can be excellent but the heat within an SCT can take between 1 to 3 hours to dissipate. It's best to keep such scopes cool as they are slow to release their internal heat which is amplified by the secondary mirror.

Did not consider the point about heat, thanks. It had been in my car all day during a road trip. Temperature got very cold at night (I was in a very arid part of California with day/night temperature extremes). Hmmmm ... not sure what to do when I need to drive to a site that's hours from home, seems like I would always encounter this issue ?

[Demonperformer]

8 hours ago, Sedna said:

not sure what to do when I need to drive to a site that's hours from home

Put together some kind on insulated air-tight box that is big enough to hold the scope (which can be removed from the mount). Get it cold at home (put a bag of ice in it for a couple of hours) make sure it is dry and put the OTA inside? Or maybe one with a peltier cooler (use the car as a power supply?). My DIY skills could be written on a postage stamp without defacing it, but I'm sure a thread on the DIY board would turn up lots of ways of making soemthing that would do the job.

[Sedna]

Update-- I drove out to Malibu to observe the planets and WOW! Much better this time, maybe because my telescope was not put through such drastic temperature changes? I could plainly see the southern polar ice cap of Mars, as well as some black surface details. Saturn was absolutely stunning! Could see ring gaps and that thin red band in the northern hemisphere, as well as the greenish color of the northern pole. Felt like I was looking at it through the window of a spaceship. Jupiter was also very crisp with lots of atmospheric details! Finally!

Very strange, because all things considered these were much worse seeing conditions than the site I mentioned in the first post. Lower elevation, higher humidity, lots of light pollution from LA. Go figure!

[Demonperformer]

That is really good news.

As for the logic ... ummm ....

[mikeDnight]

1 hour ago, Sedna said:

Update-- I drove out to Malibu to observe the planets and WOW! Much better this time, maybe because my telescope was not put through such drastic temperature changes? I could plainly see the southern polar ice cap of Mars, as well as some black surface details. Saturn was absolutely stunning! Could see ring gaps and that thin red band in the northern hemisphere, as well as the greenish color of the northern pole. Felt like I was looking at it through the window of a spaceship. Jupiter was also very crisp with lots of atmospheric details! Finally!

Very strange, because all things considered these were much worse seeing conditions than the site I mentioned in the first post. Lower elevation, higher humidity, lots of light pollution from LA. Go figure!

That's great! Perhaps the lower elevation created a more settled atmosphere, and the higher humidity may have been an indicator of this. My own observing site is low down in a valley surrounded by moorland and trees, and not far from a river. Often there's a light mist, but the planetary seeing is generally pretty good. When i take my scope up onto the moors, the air is more turbulent and field trips seem to offer little advantage to me. It seems counter intuitive at first glance!

As for keeping your scope thermally stable, I'd suggest keeping it out of direct sunlight during transportation, perhaps by covering it with a reflective foil or something. As long as it is kept as close as possible to the surrounding air temperature you stand a good chance that it will give some impressive views. Newtonians and refractors are not nearly as heat sensitive as Schmidt Cassegrains and Maksutov Cassegrains, so for long field trips in a hot vehicle, they would make a good alternative instrument choice. However, your scope sounds very capable! ☺

 

[Waldemar]

Thought of this solution?: http://lymax.com/

 

[Sedna]

7 hours ago, mikeDnight said:

That's great! Perhaps the lower elevation created a more settled atmosphere, and the higher humidity may have been an indicator of this. My own observing site is low down in a valley surrounded by moorland and trees, and not far from a river. Often there's a light mist, but the planetary seeing is generally pretty good. When i take my scope up onto the moors, the air is more turbulent and field trips seem to offer little advantage to me. It seems counter intuitive at first glance!

As for keeping your scope thermally stable, I'd suggest keeping it out of direct sunlight during transportation, perhaps by covering it with a reflective foil or something. As long as it is kept as close as possible to the surrounding air temperature you stand a good chance that it will give some impressive views. Newtonians and refractors are not nearly as heat sensitive as Schmidt Cassegrains and Maksutov Cassegrains, so for long field trips in a hot vehicle, they would make a good alternative instrument choice. However, your scope sounds very capable! ☺

 

Thanks! Yeah, my intuitions were totally defeated here, but I'm so glad that I finally got the planet viewing experience I'd been craving. I keep the SC tube in a box in my trunk when I'm driving, so no direct sunlight--however, it can still get really warm in that trunk, especially on long car trips. I think for planetary viewing, I will save myself the hassle of these long trips

[Sedna]

8 hours ago, Demonperformer said:

That is really good news.

As for the logic ... ummm ....

The logic baffles me too at first, but I think it's really about the temperature differences my SCT suffered on the first trip. This time I stayed closer to Los Angeles, where the temperature changes at night are not so drastic. At any rate, I'm not complaining!

[Waldemar]

2 hours ago, Sedna said:

Thanks! Yeah, my intuitions were totally defeated here, but I'm so glad that I finally got the planet viewing experience I'd been craving. I keep the SC tube in a box in my trunk when I'm driving, so no direct sunlight--however, it can still get really warm in that trunk, especially on long car trips. I think for planetary viewing, I will save myself the hassle of these long trips 

It may get very warm in the trunk, because your exhaust runs right underneath...

[Sedna]

2 minutes ago, Waldemar said:

It may get very warm in the trunk, because your exhaust runs right underneath...

Good point. Thanks.

[Stu]

In the car with aircon on might help!

[Swamp Gas]

5 hours ago, Waldemar said:

Thought of this solution?: http://lymax.com/

 

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