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Mars 17/02 sketch with clean mirror

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#1 Kris.

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Posted 17 February 2010 - 01:46 PM

a break in the clouds yesterday gave me the opportunity to look at mars with a cleaned mirror of the 8" which was very dusty. i also checked the position of my 12" mirror, i found the mirror clips to be tightened *very* much, which may have resulted in pinched mirror edges what might explain my dissapointing views of mars with it so far :question:


dirty mirror:

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clean(er) mirror :)

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lack of time and being tired, i chose not to set up both scopes, but only the 8" on GEM. seeing was quite good, transparancy as well, and i had the impression the view i got was probably the sharpest or 'best looking' so far this year. perhaps because of the cleaned mirror? mars just looked 'nicer'.

immediately apparent is the shrunken north pole cap and limb haze or clouds at both edges and around the south polar area, left and above Hellas. a lot of dark area around the npc, (hyblaeus and utopia,..) with two darker spots.
Nodus alcyonius was spotted as wel as some fuzzie dark markings at boreo syrtis. a first time for me.
at moments i think to have seen a (small) brightening where elysium is, bordered at the right with a dark streak.

Libya and aethiopis (the areas left of syrtis major) were easily seen as lighter than the other northern dessert plains. aeria, right of syrtis major, looked very dusty or cloudy. syrtis major itself showed detail within in the form of darker streaks. there seemed to be a faint division (hesperia) between mare cimmerium and mare tyrrhenum

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good luck with your observations!

#2 S1mas

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Posted 17 February 2010 - 01:51 PM

Very impressive Kris. I liked that soft glow around Mars - seems you cleaned your mirror well :) Thanks for sharing.

#3 BillP

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Posted 17 February 2010 - 01:53 PM

Wow....dirty mirror is an understantement :shocked: But great rendering!! :waytogo:

We should all agree to view Mars at the exact same UT date/time and do a sketch. Would be interesting to see each person's interpretation of Mars at the exact same moment :)

#4 Kris.

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Posted 17 February 2010 - 02:07 PM

S1mas: i used photoshop to render the glow, i've been thinking about adding that for a long time to improve the 'eyepiece-view' :) the pencil sketch this time was not scanned but photographed with a digital camera as Alexis suggested, to improve the subtle color variations. the scanner would not 'catch' them well enough. seems to work!

Bill: there was even some cat-hair and spiderweb-rag on it as well :whistle: that's what happens when the scope has been out for half a night about twenty times since last summer with the end cap removed!
i agree about your idea, there are already lots of sketches being posted here to compare our views!

#5 cildarith

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Posted 17 February 2010 - 04:12 PM

Beautiful sketch, Kris! :bow:

Looks like you did a good job with the mirror as well!

#6 Jef De Wit

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Posted 17 February 2010 - 04:27 PM

Kris
I'm jealous about the amount of detail you see... maybe I'm going to clean my mirror :)

#7 dweller25

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Posted 17 February 2010 - 04:43 PM

Excellent Kris, I think the dark streak to the right of Elysium is the feature I caught a few hours earlier. Thanks for posting.

#8 ladip63

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Posted 17 February 2010 - 05:25 PM

Really nice Kris:D
Can't wait to see more:D

Lynn

#9 Tommy5

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Posted 17 February 2010 - 08:39 PM

really nice Mars sketch Kris, to find detail inside Syrtis Major during this poor opposition is no mean feat, congrads.

#10 frank5817

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Posted 17 February 2010 - 10:16 PM

Kris,

I have worked with mirrors that looked worse than yours but one does feel much better knowing the primary mirror is clean. Pinched optics on the other hand can be very bad for good resolution and it does not take much to ruin the view.
Beautiful Mars sketch, I think I like the way it looks above all your other excellent sketches. Much subtle detail as you pointed out.:waytogo: :bow: :rainbow:

Frank :)

#11 CarlosEH

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Posted 17 February 2010 - 10:40 PM

Kris,

A truly outstanding observation of Mars! You have recorded a wealth of detail over the red planet. This has to be one of the finest observations of Mars of the current apparition. Your Mars observations using a dirty mirror have been excellent but this is your finest to date. I have labeled the major albedo features noted. Thank you for sharing this fine observation with us all.

Carlos

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#12 Kris.

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Posted 18 February 2010 - 11:19 AM

thanks everyone, i know you shouldn't clean your mirror untill it's very dirty, and i thought it was time! i'm more interested in the difference with the 12" with the pinched mirror clips!

actually this opposition isn't so poor at all Tommy, considering the oppositions to come... i'm kicking myself i quit sketching mars last opposition when it dropped below 12 seconds of arc :foreheadslap: i now consider anything above 10" 'prime observing time'!

i've seen some similar amount of detail inside syrtis major in the past: sketch 1, sketch 2, sketch 3.

i can only dream about seeing this amount of detail :jawdrop:






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