Mars - Realistic Expectations?

[Guest]

I've viewed Mars twice now and haven't been that impressed with the results. It just appears to be a blank orangey disc to my eyes. I don't know if there are any active dust storms at the moment. I can't see any sign of a polar ice cap. 

Equipment used 8" F6 Dobsonian, with 240x or more magnification. 

Are my expectation of seeing more than just an orange disc, unrealistic? 

[John]

I saw clear dark markings (probably Syrtis Major and other features) and the South polar cap with my ED120 refractor at around 200x about three weeks ago.

Your dob should be doing as well I would have thought. Unless a major dust storm has sprung up on the planet since I observed it last. That can lead to a largely plain orange disk even at opposition

 

 

[Rob]

Between here and October it will increase in detail seen. Newt owners require a perfectly collimated scope. Also early morning (2am/3am) seems to be the best observing time with a more steady atmosphere.

Finally.. don't push the magnification too hard. I find 200/240x most night's is good. On the rare very good seeing night's you could push 300x

Enjoy the Mars session

Rob

Edited August 7, 2020 by Rob

[Waddensky]

Features on Mars are a bit subtle, and require good seeing and a well-collimated scope as said. 240x may be a bit on the high side for an 8". Did you observe Jupiter with the same magnification? What kind of details did you see?

[Guest]

1 hour ago, Waddensky said:

Features on Mars are a bit subtle, and require good seeing and a well-collimated scope as said. 240x may be a bit on the high side for an 8". Did you observe Jupiter with the same magnification? What kind of details did you see?

https://stargazerslounge.com/topic/355261-early-morning-gas-giants/

[Guest]

9 hours ago, John said:

I saw clear dark markings (probably Syrtis Major and other features) and the South polar cap with my ED120 refractor at around 200x about three weeks ago.

Your dob should be doing as well I would have thought. Unless a major dust storm has sprung up on the planet since I observed it last. That can lead to a largely plain orange disk even at opposition

 

 

I've got a feeling that the collimation may not be as good as it could be.  I've going to order a collimation cap and Cheshire soon, for the job.  I'm not going for the laser variety, at the moment.

[Guest]

10 hours ago, John said:

I saw clear dark markings (probably Syrtis Major and other features) and the South polar cap with my ED120 refractor at around 200x about three weeks ago.

Your dob should be doing as well I would have thought. Unless a major dust storm has sprung up on the planet since I observed it last. That can lead to a largely plain orange disk even at opposition

 

 

I thought I noticed some CA at the edges of the disc, but I'm wondering if my eye was playing tricks with me, as I shouldn't be getting that with a Newtonian reflector!  I've seen that on the Venusian disc too!  What could be causing that?

[BGazing]

17 minutes ago, merlin100 said:

I thought I noticed some CA at the edges of the disc, but I'm wondering if my eye was playing tricks with me, as I shouldn't be getting that with a Newtonian reflector!  I've seen that on the Venusian disc too!  What could be causing that?

If they are top and bottom (blue top red bottom, inverted in newton), it's atmospheric dispersion. If the target is low enough and your aperture big enough, it becomes visible.

Other orientations are chromatic smear due to poor seeing. You may get both of them together.

I've checked your Jup/Sat observing thread, dispersion is easily visible in the pictures you have taken...

Edited August 7, 2020 by BGazing

[Nik271]

Dear Merlin100,

I also find details on Mars tricky to see.

To illustrate, here is an unedited picture which is pretty close to what I saw this morning (5am) with a Skymax 180 at x270. It took me some time to convince myself that there is a large dark region in the south hemisphere. 

Marsnoedit.tif

I also found that a red filter improves the contrast a bit, with the filter the view resembles the second picture edited  (obtained after sharpening and contrast boost).

Mars.tif

Clear skies,

 

Nikolay

Edited August 7, 2020 by Nik271
used wrong username of OP, corrected a typo

[Guest]

Proto Star is the ranking of the member.😉  The member's name is above in the grey banner.

[Nik271]

Sorry, that was silly of me. I corrected it. This was my first post

By the way I found this very useful link in a post from  paulastro on Monday. The web page by Ade Ashford displays exactly what features should be visible on Mars at any given time between now and December 2020.

Previously I used Stellarium but I found that the photos there don't resemble what I can actually see...

Nikolay

 

 

[Rob]

I use this little tool..

https://skyandtelescope.org/wp-content/plugins/observing-tools/mars_profiler/mars.html

Rob

Edited August 7, 2020 by Rob

[inFINNity Deck]

Dear Merlin100,

when visual observing one has to be patient. Seeing is constantly changing and one has to wait for those short moments when it is at its best. Yesterday morning at around 3-4 am I was observing Mars with my C11 EdgeHD and a TeleVue Panoptic 41mm eyepiece. During moments of good seeing I could clearly see the icecap despite this low magnification of 68x. I then swapped the eyepiece for a 2x PowerMate and ZWO ASI290MC and ADC and shot the following image.

Nicolàs

[johnturley]

I suspect that there is some dust storm activity at the moment, although not a blanket covering (at least not at present) as happens some years, as I'm finding that the dark markings are not standing out as clear as usual, but the south polar cap is quite clear.

John 

Edited August 7, 2020 by johnturley

[John]

8 minutes ago, johnturley said:

I suspect that there some dust storm activity at the moment, although not a blanket covering (at least not at present) as happens some years, as I'm finding that the dark markings are not standing out as clear as usual, but the south polar cap is quite clear.

John 

Why is it that dust storms seem to coincide with favourable oppositions I wonder

 

[johnturley]

7 minutes ago, John said:

Why is it that dust storms seem to coincide with favourable oppositions I wonder

 

I'm sure its no coincidence, they often happen around the time Mars is closest to the sun (Perihelion), and blanketed out the view of Mars around the times of the favourable oppositions of 1956, 1971, and 1973 (later stages), however 1988 and I think 2003 were not affected, at least not to the same extent. In 2018 there was a significant dust storm but it occurred (unusually) some time before perihelion. If perihelion occurs when Mars is distant from the earth, as during the aphelic opposition season, you wouldn't notice major dust storms from earth based telescopes.

John 

[Ags]

5 hours ago, John said:

Why is it that dust storms seem to coincide with favourable oppositions I wonder

Mars has a Dust Cycle of around 18 years I think. Winds blow dark regions clear of dust, darkening them, causing the planet to absorb more energy from the sun, causing more wind (and leading to media reports of "global warming on Mars"). It reaches a tipping point and when the sun is strong on Mars (corresponding to a point in its orbit we would call a favorable opposition) and the extra heat in the Martian air blows up into a global dust storm. This causes dust to settle on all the dark regions, lightening them slightly and cooling the planet, so it takes years before the next global dust storm. 

There was a global dust storm last opposition, so the contrast in dark regions will be lower this time.

I looked at Mars with my C6 a couple of weeks ago - the polar cap was very prominent and dark regions were quite visible. It does seem that some people's eyes struggle to see details that are very apparent to other observers - could it be related to the high surface brightness and redness of the planet?

Edited August 7, 2020 by Ags

[paulastro]

I think it's a matter of patience and observing for periods off sustained viewing waiting for the odd moments/minutes of good seeing for the detail to pop out.  This takes practice of course. 

The early hours of this morning was a case in point.  I was at the eyepiece from 1.50 until 3.25am.  The conditions were quite variable, both cloud and seeing wise.  At time there were minutes on end where not much was visible, but overall I was very pleased with what I saw.  Quick views hoping for immediate success will rarely cut the mustard with Mars.

For what it's worth, I wea using my SW 120ED with binoviewer and Orhos.  Mag from around x200 to x275. At variouse times I used a #21 red filter.  Sometimes I use a Baader Contrast Booster, but not last night.

Of course the worse the seeing is, the more difficult it will be with larger apertures.  In the conditions I generally have, any scope over 6 inches or so would only be of benefit on the odd occasion.

Edited August 7, 2020 by paulastro

[Guest]

2 hours ago, paulastro said:

I think it's a matter of patience and observing for periods off sustained viewing waiting for the odd moments/minutes of good seeing for the detail to pop out.  This takes practice of course. 

The early hours of this morning was a case in point.  I was at the eyepiece from 1.50 until 3.25am.  The conditions were quite variable, both cloud and seeing wise.  At time there were minutes on end where not much was visible, but overall I was very pleased with what I saw.  Quick views hoping for immediate success will rarely cut the mustard with Mars.

For what it's worth, I wea using my SW 120ED with binoviewer and Orhos.  Mag from around x200 to x275. At variouse times I used a #21 red filter.  Sometimes I use a Baader Neodium, but not last night.

Of course the worse the seeing is, the more difficult it will be with larger apertures.  In the conditions I generally have, any scope over 6 inches or so would only be of benefit on the odd occasion.

I have access to a 4.5" reflector, if you think that may make a difference?🤔 There are supposed to be a few viewing opportunities over the next couple of early mornings... 

[paulastro]

1 minute ago, merlin100 said:

I have access to a 4.5" reflector, if you think that may make a difference?🤔 There are supposed to be a few viewing opportunities over the next couple of early mornings... 

I'd certainly give it a go.  If it's of sound optical quality and well collimated it should show something when seeing allows.  The only difficulty may be if you can get the necessary mag out of it.  Personally I need at least  x150 though I do have aging eyes 🙂.

[Rob]

14 minutes ago, merlin100 said:

I have access to a 4.5" reflector, if you think that may make a difference?🤔 There are supposed to be a few viewing opportunities over the next couple of early mornings... 

Yes, for sure. I think it was back in 2003 Mars opposition I had a Helios Skyhawk 114mm. It  was a joy for Mars that year. I saw a lot more detail than I thought I would. Needs spot collimation mind you!. Even slightly out makes a major difference

Edited August 7, 2020 by Rob
typo

[westmarch]

I sympathise with the OP and have always struggled to make out any detail on Mars.  I chanced to wake this morning at 04:15 and noticed Mars prominent to the south.  Not wanting to wake my wife, I couldn’t drag out the dob and instead used my old ETX 90 from another window.  

The sky was very transparent  and seeing was also remarkably good.  Indeed, I was able to push magnification up to x280!  I could clearly see the South Polar Cap and a darker southern hemisphere corresponding to Mare Serenum but

I agree with:

3 hours ago, paulastro said:

I think it's a matter of patience and observing for periods off sustained viewing waiting for the odd moments/minutes of good seeing for the detail to pop out.  This takes practice of course. 

Quick views hoping for immediate success will rarely cut the mustard with Mars.

I broke my duck with Mars this morning but it required patience, good conditions and 45mins of sustained viewing to tease out the features.  I tried a variety of filters but in the end settled for unfiltered vision.

Good luck and persevere.

John

[JeremyS]

I suggest you keep an eye on the BAA Mars Section Director's Mars blog for news about dust storms etc.

[Rob]

3 minutes ago, westmarch said:

I sympathise with the OP and have always struggled to make out any detail on Mars.  I chanced to wake this morning at 04:15 and noticed Mars prominent to the south.  Not wanting to wake my wife, I couldn’t drag out the dob and instead used my old ETX 90 from another window.  

The sky was very transparent  and seeing was also remarkably good.  Indeed, I was able to push magnification up to x280!  I could clearly see the South Polar Cap and a darker southern hemisphere corresponding to Mare Serenum but

I agree with:

I broke my duck with Mars this morning but it required patience, good conditions and 45mins of sustained viewing to tease out the features.  I tried a variety of filters but in the end settled for unfiltered vision.

Good luck and persevere.

John

As they say.. 'Mars is hard!' that applies to landers & observers. Its been a project for me for over 20 years now. I've had amazing sessions and darn right awful sessions. As you say 'persevere' it will reward you, its what being an Astronomer is all about.

Rob

[Knighty2112]

A good filter brings out details better. I bought the Celestron Mars filter the other year, and it works a treat in teasing out more info. I tend to find I get better, sharper views in my ‘fracs than with my 10” Newt with it, although it works OK in the Newt too. If you don't want the expense of a filter like that then you can use some yellow or green planetary filters that work pretty good too, although not as good as the Mars filter.