JSC (AV) - Skylab 4 - Crew Day Off Activities - TV 81-8 / Science Demonstration (Immiscible Liquids) - TV 102 Part 2

Description

FR# A219 SKYLAB 4 KINESCOPE TAPE 8, PART 1 of 3 What I'd like to show you here is a closeup picture which is the first evidence we have of the Comet Kohoutek with a sunward spike. The picture was taken - it's a polaroid picture - which was made off the white light coronagraph display. And although it is indeed very faint, the pictures that we will talk about, and have talked about, are evident, at least on the photograph, as we will hope that they are on TV. The first feature, the one which is most easily noticed, of course, there's the bright dot on the ceter, and that's the coma. The second feature is just the very start of a tail, which you see right here, on the righthand side, again it's very faint, but I belive it's discernible, and lastly, the sunward spike which comes in from the lower left, maybe 30 degrees below the horizontal. We were able to see this feature, this is perhaps our best picture - we were able to see this feature for three different times or so during the time period which we were observing it on the white light corona- graph TV display. Most of the time, it's just a very bright dot, representing the coma - it is in evidence to us - (garble) gave us a hint before we went EVA that we might see the sunward spike and kept us looking forward - looking for it. on my right, if you can or out of the camera there What we'd like to do tonight is to show you some of the stretches which we've made of the Comet Kohoutek. We have no way of giving you live TV of the comet, unfortunately, so we've tried to make stretches from day to day, especially after perihelion when it became most evident and most dynamic, and that way, try to relate to you some of the features which eventually will show up on some of the film we bring back, but we hope will give you an insight - earlier insight into what the comet appeared like, and its changes. The first one we're showing you here is a overall impression we have, and we did not make sketches at the time, of the comet before peribelion, and again, this is just very crude, and it's just meant to give you a data point at which to start out at which to start so you can see the change in the following sketches. Again, a quick look - you see a white ball with just a bare evidence of a tail. When you get a little better dark-adapted, you can see a white ball, of course, which is the coma, and a tail leading backward, and I would say that the longest we A219 - Page 2 ever saw it, when it was still visible to us, was something on the order of one to three degrees, depending upon how well dark-adapted you were. And this is all pre-perihelion. Uh, we're estimating here roughly 10 days or so ahead of time when it got very close to perihelion, of course, we could not see it either Here's the way we saw it on our EVA day. We've already given you this picture once before. We've reformated it a little though. Also on an earlier TV, just before this, I tried to give you a closeup of what we saw on the white light coronagraph TV display, which did have a slight evidence of the sunward spike. What we're showing here is first of all the coma, very bright to us, the appearance or color of it was yellow and most noticeable was the yellow- white spike protruding forward, and we say yellow-white because we have the impression there was a little yellow in there, but relative to the coma and relative to the tail, it did not contain as much yellow. The sunward direction was here, and in the TV which I have shown before this, a closeup, that spike is going toward the sun which we could talk about further as far as orientation of that picture. Right now, I'll press on though to tell you a little bit more about what this bottom drawing is - represents - they are very crude pictures of isotopes which means isophotes which means just our mental image of what would be equal intensities of radiation. Of course, the center of the coma is the hottest, then it tends to degrade as you go further out. And then, these are lines of equal intensity back here, and they're rather sharp, in that they are flat on the back. This is a contrast to what we have seen later on. The size of this was around 4 to 5 degrees, that we could see over- all, and again, this was the day after perihelion, day 363. On the following date, 364, the tail became much more evident to us - it was significantly longer as the tail swung around and allowed us to see more of it from the side. And it also was the orangest if there is such a word it was most orange as we have seen before and after, and the sunward spike was yellow - very definitely yellow, and the tail was yellow, with perhaps a little bit of orange in it, but the coma itself most certainly was very orange. On the following day, the tail was even longer than the previous day, which was 6 or 7 degrees long. Here it was not quite as orange, and we still noticed, as I should have pointed out in the previous drawing, that there is a sunward spike and a little bit of A219 - Page 3 material in between it. The sunward spike had faded quite a bit - I shouldn't say sunward, because perhaps that's misleading. It was not always right on the same axis as the tail, which was pretty much anti-solar now, but it was pretty close to it. It was pretty tough for us to estimate which was really pointed straight at the sun and which was straight away, but there was a slight angle between the two. Colors here were yellow-white for the spike in front, and yellow primarily for the coma and the tail. Now we had some assessment of the length of this by finding out that Venus was 15 degrees away and Jupiter was 19 degrees away, so we had a reasonable way of making an estimate of the length of this tail, and we came up here with an estimate of 7 to 8 degrees. Again, these were pictures, or observations out of the Command Module, and one of the windows in the STS structural (garble) section, Window No. 3. Now this day, one thing that really occurred to me as I looked at it, it looked very familiar, and I couldn't figure out why until I all of a sudden realized that it had very much the appearance as we were looking at it of a rocket which is burning in the upper atmosphere, say the second stage of one of the Apollo series, and you see the very intense light white center, which is the exhaust plume itself right close to the nozzle, and then because the atmospheric density is very low, you find that the plume tends to spread out very rapidly, but very faintly along the side, and then you see the major plume protruding backwards, and it looked as though we were seeing a rocket exhaust plume, maybe 45 degrees or so off the axes. Again, here are the drawings of equal isophotes - or isophotes, if you will, lined in equal intensity, and here they are more elliptical, as you see. There's again, what you really ought to do to get a proper image of these is to integrate, if you will, between these two. Here we try to just draw schematically what it is, here we've tried to put a little more into it in the way of intensity information, but you really have to combine the two. Neither one tells the story. This is the first day of the year, the New Year Day, and here we estimated the length and ---as decreasing around 5 or 6 degrees. Still yellow-white, and here we could not fade say that this spike was here at all. Uh, sometimes when you looked at it, you thought you saw it, and other times you didn't. So rather than mislead, we said well, it's questionable - maybe our mind's eye pictures it but our eye really doesn't. And again we saw this material coming off the side of the coma which we could not really trace - we could not trace this one back, for example, but you could certainly trace the major stream of the tail all the way back, and again, these lines of equal A219 Page 4 intensity could now be more elliptical as opposed the first day after peri as opposed to what we saw the first day after perihelion. And lastly, we have today, and here, now it really isn't a spike at all, and we drew it in yesterday - today we can't say there's any at all - probably not, we cannot see it at all, even in our mind's eye, we gradually talked ourselves out of it the day after it had vanished, and the tail again is a alittle bit shorter, 4 or 5 degrees now, and as I pictured it - - it tended to be a little bit fatter in my estimation, but again this is qualitative, and the lines of equal intensity resemble what we've seen before, and I guess the general, overall impression is that the tail is becoming a little bit shorter, as at least the evidence of the tail is becoming shorter as it moves further away from the sun, and also the color now is just plain white - we see no evidence of yellow at all. Okay, Bill would like to add something. Ed has it in the drawing - the tail thatyou see here has sort of a ragged appearance. This was the first thing that impressed me - the fact that it was fading and that the tail was taking on a ragged appearance back toward the tail - the end of the tail. Well, that's it for now - from Kohoutek observations headquarters - we'll try and keep you up todate as we see any changes. It's been most interesting for us, and uh, we hope we've been able to give some useful information to you on the ground. I wish you all could see it.

Collection

Records of the National Aeronautics and Space Administration

Series

Moving Images Relating to Documentary Stock Footage