火星 ALPO-Japan Latest

Mars Image 2020/05/20(UT)

Clyde Foster
C.Foster

解説(安達)/ Comment by Makoto Adachi
 前日も今日もオリンピア山(Olympus Mons;135W,+25)は赤っぽく記録されてた。リムは北半球が明るく、ダストベールの濃さは、
この付近では北半球が濃いことを示している。

Olympus Mons (135W, + 25) was recorded reddish the day before and today. The limb is bright in the northern hemisphere, and 
the density of the dust veil indicates that the northern hemisphere is dark in this vicinity.

(by 1 observations; reported by Makoto Adachi)


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Clyde Foster
I have become quite intrigued over the last week as the dark markings on the SPC have become more evident. 
Masami Murakami of ISMO/CMO has kindly sent me some background information.
A dark marking in the SPC was apparently first observed by W H Pickering on 22 May 1894, as noted by Percival Lowell in his book of 1895, 
prompting him to develop a proposal of a polar sea. 
Two large polar markings were subsequently identified and named by E M Antoniadi which are shown on his map of 1924. 
From what I can gather, measuring the location, it appears that the main polar dark area seen in my image is Depressio Parva. As always, 
I am open to comment and correction.
Olympus Mons is at lower left, almost on the terminator, and there is again a slight cloud formation over Arsia Mons at centre left. 
It was again nice to get something reasonable out of rather poor seeing conditions, 
although a pity that the R and IR are negatively affected by the edge artrifact.

[Clyde Foster:Centurion,South Africa]

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