20051018 – Wrapping up with Mars

Session Name: 20051018.2115

Location: 59th & 6th, Entrance to Central Park, NYC
Site Classification: Urban
Date/time: 17 Oct. 2005, 9:15pm ~ 12:25am
Tripod Mounted Binos: Takahashi FS102, F/8 102mm refractor

Eyepieces
EP :: AFOV :: MAG :: TFOV
Plossl 32mm :: 50° :: 26x :: 2.0°
Nagler 13mm :: 82° :: 63x :: 1.3°
Nagler 9mm :: 82° :: 91x :: 0.9°
Nagler 6.5mm :: 82° :: 126x :: 0.7°
Nagler 5mm :: 82° :: 164x :: 0.5°

NELM –
Perseus - m5.24, HIP 14043; m5.04, HIP15219; m4.99, 4 stars (trapezoid) between Mirfak and delta Per.

Conditions: Full Moon & Mars in a clear sky. Weather history for 18 Oct. 2005 at wunderground.com


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This evening wrapped up a 3-day streak of observing from the south end of Central Park, in the path of Jose de San Martin and his defiant horse. (scroll down the page).

I had selected this spot because it was a short walk from my house, Moon was full, and the weather forecasts were not promising . I wasn’t planning on doing any deep sky observing so I didn’t need a large dark sky; the section of the Ecliptic where Moon and Mars are situated these days was readily available. Wrapping up from this temporary location is prompted by the fact that features exposed from libration have been masked by the evening terminator. It was a good ride from here, meeting many friendly persons, new faces and variety from those I meet at TotL.


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Of the nearly 2 dozen persons that stopped by, Caroline, and later Jesus and Stan, stood out from the rest. Caroline arrived during setup. She mentioned that she had stopped by the other night with a friend, but they had to leave rather quickly. She did take the opportunity to look briefly at Moon that left an emotional impression. Tonight, Caroline stayed for maybe a half hour or more, keeping me company and engaging in conversation. The waning Moon and brilliant, orangy-red Mars were the objects of interest. She commented that Mars looked more reddish naked eye than through the telescope. She asked whether there is an observatory in New York City, which I told her about Columbia University’s public outreach program, and the amateur led one conducted at TotL.

Much later, Jesus and Stan came by separately. Jesus & Stan stayed with me a bit talking about all things. Stan had showed a photograph of Moon and Mars taken a previous night on his digital camera. Jesus was particularly interested in buying a scope. I emphasized learning the sky and binoculars. I suggested that he attend one of NYC’s astronomy club’s, AAA, public sessions at Carl Schurz Park. He can look through a variety of scopes. Of course, I mentioned TotL, but there is no regular scheduling. Moon, Mars, and the Pleiades were shown to them. When I pointed out where we looking at the Pleiades, Jesus said he could see six stars bunched together.


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The take away for this night was Mars. I've had my best observations of the planet thus far. Aperture and magnification were major contributors to the great views. Yesterday’s observations begged for this, so I stepped up from the TVR 70mm refractor to the Tak 102mm refractor. A broader collection of EPs helped out. In all, I was pleased with the observations ranging from 92x to 164x. I used the Nagler 13mm, 63x, very quickly seeing that the Mars appeared small. I didn't look long enough to judge how details of Mars appeared.

It was later around 10:45, when I focused on Mars. It had risen higher in the sky and appeared much better than earlier. In the times I was left to my own, I was able to get some quality observing time. The drawing below is an impression of what was seen. This one corresponds to what was detected at 164x magnification. The outline across the top of the lower, large expanse, I associated the astronomical symbol for Scorpio, since there were two humps that saddled the center of the disk, and on Mars western hemisphere there was a sharp dip.



I don't know Mars well, so some of the features I think I saw include:
- Mare Erythraeum. The large expanse which had low contrast, but enough to detect the humps and a brightened limb along the Martian southern limb.
- Sinus Meridiani. Unmistakeable, darkened section, on the eastern limb (field reverse drawing).
- Chryse. A brightening white area/spot in the center of the disk. I only detected 1 under 164x, with 126x I saw two white spots.
- Mare Acidalium. Another conspicuous dark feature across the top, but I did not see the same kind of low contrast surrounding area.
- As noted, there was a sharp falling off from the second "hump". I haven't found the name of this feature yet or the name of the lighter ground (non-mare?), but for such a shape I would think it received one.

I continued with the exercise of sketching Moon. I concentrated northeast of Mare Crisium, the terminator was now providing the relief I am accustomed to seeing. A “valley” ran from the northeast corner of M. Crisium, the mountains in a discontiguous line along the northern edge of this valley into the terminator. I suspect that this was part of the rim of Mare Anguis. At least six craters and two elevations now appeared on the floor of M. Crisium.


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After I packed up my gear into the snowboard bag and backpack, I spent some time assessing the NELM. I was shocked. It was around midnight, and Cassiopeia was nearly straight up. From where I stood, I could easily make out both Upsilon stars, and Novi. (I have always been confused by this name. I got it from TheSky6y, but I have seen this refer to gamma Cas.) Novi, HIP 4151, is a m4.8 star 36’ ENE of gamma Cas. 6 stars of Pleiades were easily counted, Jesus had counted them earlier. I could see all of Hyades, in addition to resolving theta^1- and theta^2 Tau with no difficulty.

Walking to the east around the trees, I could see Perseus. Here I searched for my standard candlesticks which I judge the NELM in the Corridor. I was able to see as faint as m5.2, though this required effort and averted vision. Four stars inside of Mirfak and delta Per, a quadrilateral, was seen, effort required for the southern one near Mirfak.

I anticipate that I won’t come to this spot in the near future, returning to TotL. TotL is not as busy, horizons are not as badly obstructed, the area of sky is significanltly larger, and the Team assembles there. I would have liked to compare-n-contrast these observations in the different instruments and hear the impressions of others. Soon enough – and Mars doesn’t seem to be going anywhere except coming closer.

peter