8 December 2007
| This is the way humans are: We question all our beliefs, except for the ones that we really believe, and those we never think to question.
Andrew "Ender" Wiggin |
| Observing Location | PSC | ||||||||||||||||||||
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| Observational Period | 1300-1330 EST | ||||||||||||||||||||
| Atmospheric Conditions |
The forecast says that a cold front will pass through this afternoon and clear out the clouds, but that the temperature will rise to above 40°F for the first time in a week. I had been seeing alternating sunny skies and light cirrus clouds out of my window all morning. By the time I got out to try a solar observation. I found the sky overcast without even a glow where the Sun was hiding. The humidity is at the high end of moderate
The clouds thinned out a bit once but I could barely make out the Sun through the welder’s glass, although it was too intense to try observing without it. When I got home it was clear again.
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| Instruments | Brunton 8x21 compact binocular w/Welco gold shade 14 welder's filter - Charlie | ||||||||||||||||||||
| Observing Party | Charlie Ridgway |
| Observing Location | PSC | ||||||||||||||
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| Observational Period | 1430-1445 EST | ||||||||||||||
| Atmospheric Conditions |
It didn’t feel as raw as it had when I was out earlier.
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| Instruments | Brunton 8x21 compact binocular w/Welco gold shade 14 welder's filter - Charlie | ||||||||||||||
| Observing Party | Charlie Ridgway |
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NASA has again delayed the launch of Atlantis. It is now scheduled for Sunday at 1521 EST. The problem is still the same and they still don’t have any idea why it is occurring.
There are four sensors in the fuel tank that all do the same thing. The procedures say that they can’t launch unless at least three of them are working properly. I remember one time in the past when they had this problem and said that they were thinking of launching anyway because there was too much redundancy built into the system and all they really needed was two of three sensors to be working. The quote I heard on the news today said that they will make a launch decision tomorrow (I don’t know if the press briefing was this morning or yesterday) and it the condition hadn’t been corrected at that time they would delay the launch again because they would be in violation of the launch constraints. Maybe some things have changed at NASA.
I have finally gotten to the NASA web page, which must be inundated right now since it is near the previous scheduled launch, and see on the splash page that the launch is now postponed until Tuesday. But on the splash page of the shuttle section it still says that the shuttle is scheduled to launch on Thursday, 6Dec07 at 1631 EST.
Based on the formula that the shuttle launch time is advanced by 23 minutes for every day the launch is delayed I think it should be launching 69 minutes earier than it was scheduled for today or around 1540 EST on Tuesday. CalSky has not updated their site with the latest launch information yet so I can't confirm that.
At 1630 tonight NASA announced that they will attempt a launch tomorrow afternoon at 1521 EST.
| Observing Location | PSC | ||||||||||||||||
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| Observational Period | 1900-1915 EST | ||||||||||||||||
| Atmospheric Conditions |
It is feeling a little moist again but it really isn’t all that bad out. The RH and BP are both dropping which is strange.
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| Instruments | Brunton 8x21 compact binocular - Charlie | ||||||||||||||||
| Observing Party | Charlie Ridgway |
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The Morning Daylight appears plainer when you put out your Candle.
Ben Franklin |
| Observing Location | MO | ||||||||||||||||
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| Observational Period | 2030-2200 EST | ||||||||||||||||
| Atmospheric Conditions |
I had put on my down jacket since I was planning to be out longer, but I didn’t put on the long-john bottoms and suffered a bit for it.
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| Instruments | SAR: Coulter CT-100 Newtonian reflector - Charlie
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| Observing Party | Charlie Ridgway |
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It seemed like everything I wanted to look at tonight was right next to an area light and I was having trouble seeing stars for the stray light getting into the eyepiece. I need to build myself a tube extension to keep light from coming in off axis through the front can and striking the lens. I also need to figure out some way of sealing off the bottom of the tube where my shroud doesn’t go all the way to the truss bar (which is uncoated aluminum so also reflective) and allows light to get right to the primary mirror when I am pointed near zenith.
I played with SAR rocking the front can in all directions and moving Mars around the FoV and the only way I could get rid of coma was to put the planet outside of the field stop in the 7:00 position and move my eye up toward 1:00 and look under the field stop. Coma is also greatly reduced when I have the chimney thumb screw loosened to focus, but as soon as I tighten the screw it cants the eyepiece to the left and coma returns. I should try lining the inside of the chimney with tape to snug up the fit and see if that helps anything.
I tried shimming the chimney with electrical tape and no matter how thin of a strip I cut there is still too much thickness to let the eyepiece slip into place and focus.
I measured the front can for an extension and it looks like I need at least 5.5” to keep off-axis light from reaching the field lens of the eyepiece.
I have a label on the front can that says my resolution is 1.2 arcseconds. But I don’t know what that means so I calculated the smallest lunar feature that I should be able to see and it has a diameter of 2.2 km (1.375 mi). That is a little more useful since Rukl, Cherrington and Grego all give crater diameters in their books.
Moon average diameter = 31.5” Moon diameter = 3475 kmSmallest Feature = (Resolution / (Diameter * 60)) * Diameter
Smallest Feature = (1.2 / (31.5 * 60)) * 3475
Smallest Feature = 1.2 / 1890 * 3475
Smallest Feature = 0.000635 * 3475 = 2.2 km
posted by Charlie at 15:53
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