Mars 22/23rd Oct 2020

[markse68]

It was clear at 8pm- had a nice view of Moon and the Gas giants snuggled up together so the evening looked promising. Still clear when I got home but by the time Id set up there was almost complete cloud cover. I nearly packed up again but a small opening to the SW persuaded me and eventually I had a good 2 or 3 hours of fabulous Mars. We seem to be back to where I started sketching with Valles Marineris central- a finger on a hand like dark formation. SPC was prominent too unlike last time I observed. Lots of intricate detail and shading in the dark and light regions- possibly the most interesting phase of Mars visually. My sketch isn’t correct- i’ve got the dark features too equatorial- they should have mostly been in S hemisphere (top half) but i think i got the forms ok.

Mark

[globular]

Nice sketch Mark - some interesting details.  Looks and sounds like you had a good session after your patience with the clouds. 

I had more cloud than was forecast but I persevered too and had some good clear spells.  However very little surface detail was revealing itself despite nice rock steady images.  I got nothing but the south polar cap, some whiteness at the north fringes and a squareish star shaped darker smudge filling the southern hemisphere.  Amazing how seeing conditions vary from place to place.

[markse68]

Thanks Glob, it is odd isn’t it how even without apparent atmospheric turbulence some days it’s clear and others a bit mushy. I guess it must be atmospheric turbulence or dirty air that’s breaking up the image without really looking turbulent? I got lucky tonight- it was very clear earlier on then degraded a bit later on. Hope you get better luck next time!

I tried to correct the errors in the pencil sketch in this from memory/based upon colour version

Mark

[dweller25]

Great drawings Mark 👍

[John]

Excellent sketches Mark

I was observing on and off (in tune with the cloud cover !) with my 12 inch dob last night and saw similar details for a while, which you have captured excellently. Those dark "promontories" sticking out into the paler areas were rather nice features last night.

As you found, the seeing took a dive later and the surface features became much vaguer.

I wondered if the south polar cap was actually a little larger last night than the last time I observed Mars ?

 

[vineyard]

Lovely sketches.  Did the polarising filters experiment work?

[dweller25]

55 minutes ago, John said:

Excellent sketches Mark

I was observing on and off (in tune with the cloud cover !) with my 12 inch dob last night and saw similar details for a while, which you have captured excellently. Those dark "promontories" sticking out into the paler areas were rather nice features last night.

As you found, the seeing took a dive later and the surface features became much vaguer.

I wondered if the south polar cap was actually a little larger last night than the last time I observed Mars ?

 

I also think the SPC was a little larger last night

[markse68]

Thanks Dweller and John

2 hours ago, John said:

I wondered if the south polar cap was actually a little larger last night than the last time I observed Mars ?

I think it must have- it was much more noticeable than last time i saw it which was only a few days prior. Astonishing to think just how dynamic Mars’ ice caps are being largely CO2!

 

1 hour ago, vineyard said:

Lovely sketches.  Did the polarising filters experiment work?

Thanks Vin! Well I tried them for the first time last night- seeing was good but not quite up to Thursday night. I was a little disappointed ☹️ They didn’t really do what i’d hoped they’d do. I’d noticed when thin clouds drift across Mars sometimes for a fleeting moment the whole S hemisphere darkened relative to the N- just like in the amazing photos others have taken. All the polarisers did was darken everything and whilst that might be useful- I need to play some more- it wasn’t what I’d hoped for and I felt I saw more without them. I wonder if it may be an eye adjustment thing and that if you could flick a switch and have the image suddenly darken them the contrast would become more apparent- maybe an lcd nd that pulsed on and off so you got that contrast 🤔 I reckon anything you put in the light path must have some negative effect on image quality/sharpness though. Not a waste of money though- should be useful for Moon

Mark

[globular]

5 minutes ago, markse68 said:

if you could flick a switch and have the image suddenly darken

I've pondered getting a filter slider...

...so you can slide a filter in and out while looking through the eyepiece.
Trouble is it will need a slight focus tweak too so won't be as immediate as we'd like.  
I might still try it though..... ?

Don't give up on your 2 filters trick - I often find some nights are better with and others better without filters - so keep trying for a while longer.

[markse68]

17 minutes ago, globular said:

I've pondered getting a filter slider...

...so you can slide a filter in and out while looking through the eyepiece.
Trouble is it will need a slight focus tweak too so won't be as immediate as we'd like.  
I might still try it though..... ?

Don't give up on your 2 filters trick - I often find some nights are better with and others better without filters - so keep trying for a while longer.

Nice idea Glob- if you could get square filters and use 2- one clear and one nd then you’d avoid the focus tweaking but i’m afraid in my scope at least the wobble induced would ruin the view. Maybe a fast acting motorised filter wheel could do it 🤔

[lunator]

Hi Mark

Very nice pics. 

I put mostvof the mushiness last night down to lack of scope cool down time, But the seeing might have been deteriorating as well. 

You got some nice detail in there

cheers 

Ian

[mikeDnight]

Excellent sketches Mark. 

[markse68]

Thanks Ian and Mike!

[procky1845]

@markse68 we must have been out sketching at the same time. Your view is basically the same as mine. Always nice to get a double confirmation of what you've seen. 😀

 

[markse68]

34 minutes ago, procky1845 said:

@markse68 we must have been out sketching at the same time. Your view is basically the same as mine. Always nice to get a double confirmation of what you've seen. 😀

 

Almost! I think you must have been sketching a bit earlier than me  Nice sketch Procky 👍