Mars on 23 Jan 2010

Canopus Lim · Post by **Canopus Lim** » Sun Jan 24, 2010 4:49 pm

The weather has cleared up and last night Mars was pretty good through the telescope. There was slight breeze, not too much haze, little to no low altitude clouds and quite high humidity hence the atmospheric seeing was good.

Mars was constantly sharp at 320x using my 12.5" Obsession dob and 5mm XO eyepiece.

Mars meridian according to Sky and Telescope applet is about 330 degrees. Although Mars is still small, if I am not wrong at opposition in few days time it will only have a diameter of 14 arc sec which is less than half the diameter of Jupiter, I could see all the features on Mars that is shown in detailed map. Syrtis Major had a bluish colour and this is the second time I saw having this colour. The North polar cap is still very large and plain easy to see. The southern cap has shrunk till it cannot be seen or just a slight glimpse of it. On 2nd Jan 2010, I could see the South polar cap and it was real obvious, now it cannot be seen (perhaps it is more visible on the other side of the globe).

http://www.skyandtelescope.com/observin ... page=1&c=y#

These are the features that I saw:
1. North polar Cap
2. Syrtis Major
3. Arabia
4. Mare Serpentis
5. Sinus Meridious
6. Sinus Sabacus
7. Manga ritifer Sinus
8. Mare Acidalium
9. Niliacus Lacus

and some more unnamed subtle features seen on Mars. I can say that the amount of detail I could see was similar or more than in the 2005 when Mars was 20 arc sec in diameter. If that time I had this scope.... I think it would have been real awesome.

All in all it was a good view and similar to that of good planetary photograph.

Attached is a link of a simple sketch I did.

http://img198.imageshack.us/img198/7546 ... idan33.jpg

For you guys who have not seen Mars, do take a look at it. Opposition is on 27th Jan. Do use at least 200x magnification as Mars is still small.....

antares2063 · Post by **antares2063** » Mon Jan 25, 2010 4:44 pm

yup mars is getting brighter...nice sketch too...will look forward to looking at saturn thru your 12.5 inch monster soon ;)

Tachyon · Post by **Tachyon** » Mon Jan 25, 2010 6:51 pm

Nice! Thanks for the description. Will be at Mauna Kea on 31 Jan to observe. Hope the weather is good!

jiahao1986 · Post by **jiahao1986** » Mon Jan 25, 2010 7:11 pm

Tachyon wrote:Nice! Thanks for the description. Will be at Mauna Kea on 31 Jan to observe. Hope the weather is good!

you are visiting Mauna Kea!? looking forward to your photos!

bowright · Post by **bowright** » Mon Jan 25, 2010 9:55 pm

That's awesome for so much details!
I can only see mars about a green beam through my 90mm refractor at 100x, polar cap not visible.
Will that be helpful to use a 2x barlow to make it 200x?

Canopus Lim · Post by **Canopus Lim** » Tue Jan 26, 2010 12:19 pm

antares2063 wrote:yup mars is getting brighter...nice sketch too...will look forward to looking at saturn thru your 12.5 inch monster soon ;)

Hey no problemo... will observe only about 11 to 11.30 onwards till at most 1am.. need to work.

Canopus Lim · Post by **Canopus Lim** » Tue Jan 26, 2010 12:21 pm

Tachyon wrote:Nice! Thanks for the description. Will be at Mauna Kea on 31 Jan to observe. Hope the weather is good!

Wow cool! My last trip there I found that the seeing conditions is good and the dark sky is fantastic. Do bring lots of warm clothes as it can be pretty cold especially at the summit of Mauna Kea when the sun sets. For the visitor centre, it is much warmer (still cold though).

Canopus Lim · Post by **Canopus Lim** » Tue Jan 26, 2010 12:25 pm

bowright wrote:That's awesome for so much details!
I can only see mars about a green beam through my 90mm refractor at 100x, polar cap not visible.
Will that be helpful to use a 2x barlow to make it 200x?

Last night I tried with my 88mm refractor. I could see the north polar cap at about 100x and Syrtis Major. At 200x, I could see more details and the shape of Syrtis Major more clearly. Is your 90mm refractor an achromat?

If it is an achromat, it will be better to use lower magnification like slightly more than 100x.. but less than 200x.

Tachyon · Post by **Tachyon** » Tue Jan 26, 2010 1:15 pm

Canopus Lim wrote:
Tachyon wrote:Nice! Thanks for the description. Will be at Mauna Kea on 31 Jan to observe. Hope the weather is good!
Wow cool! My last trip there I found that the seeing conditions is good and the dark sky is fantastic. Do bring lots of warm clothes as it can be pretty cold especially at the summit of Mauna Kea when the sun sets. For the visitor centre, it is much warmer (still cold though).

Thanks! Fortunately, there is someone to set up the scope so I just bring my camera to do some landscape photography.

bowright · Post by **bowright** » Tue Jan 26, 2010 3:05 pm

Canopus Lim wrote:
bowright wrote:That's awesome for so much details!
I can only see mars about a green beam through my 90mm refractor at 100x, polar cap not visible.
Will that be helpful to use a 2x barlow to make it 200x?
Last night I tried with my 88mm refractor. I could see the north polar cap at about 100x and Syrtis Major. At 200x, I could see more details and the shape of Syrtis Major more clearly. Is your 90mm refractor an achromat?

If it is an achromat, it will be better to use lower magnification like slightly more than 100x.. but less than 200x.

Yes it's an achromat C90, maybe a few days earlier mars was a bit small. I'll try for these days, hope it is bigger now. Or is it because I did not wait for mars to rise enough above horizon? That might be another cause. So what was your view time?