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NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring!
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Pollyannuh
User ID: 46877
5/6/2006 12:51 AM
Report abusive post | NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring!
| Quote |
For those among us who understand exactly what NASA is saying in this document, please clue me in.
Thanks.
This is the scarey part....
<<snip: "We do not yet know what to expect from this comet, so we'll rely on early Arecibo results to guide our plans..."
[link to reason.jpl.nasa.gov]
Comet 73P/Schwassmann-Wachmann 3 Planning
Background
Instructions
Goldstone Masterlog
--------------------------------------------------------------------------------
Background
Comet 73P/Schwassmann-Wachmann 3 was discovered by Arnold Schwassmann and Arno Wachmann
on May 2, 1930 at Hamburg Observatory in Germany. It approached within 0.062 AU six
weeks after its discovery, when it reached 6th magnitude. The comet has an orbital period
of 5.36 years, but due to uncertainties in its orbit, faint visual magnitudes, and relatively
close approaches to Jupiter in 1953 and 1965 that altered its orbit, it wasn't recovered until
1979. In the fall of 1995 the comet's magnitude brightened dramatically, and then in December
of that year, multiple fragments were discovered. In other words, the comet's nucleus split.
Three of the fragments, B, C, and E, were observed again during the subsequent perihelion passage in 2001.
Fragment C was recovered in August, 2005 and fragment B was recovered in January, 2006.
The comet has since split multiple times, and as of early May, about dozens of fragments
been observed. Fragment B has split into at least one large fragment and a cloud of smaller ones.
In contrast, fragment C apparently has not split (yet).
During May, 2006 fragments B, C, and most of the others will approach within 0.079 AU.
Fragment E was last observed in December, 2000. It is predicted to approach within 0.051 AU
several days after the other fragments, when we hope to observe it, presuming, of course,
that it still exists.
Sekanina (1989) estimated a pre-breakup (prior to 1995) diameter of about 2 km.
Toth et al. (2005) estimate that fragment C (prior to recent splitting) had a diameter of 1.3 km.
Fragment C is the largest and (as of early May) is already bright enough to see in binoculars.
Fragment B is also visible in binoculars but it's fainter than fragment C. The other fragments
require a telescope to observe.
These will be combined Goldstone and Arecibo observations.
Goldstone observations are scheduled on May 9, 12, 14, 21, and 23 and Arecibo observations are
scheduled on several dates between April 30-May 22. We know little about the sizes and rotation
periods of the fragments, so it's hard to estimate the SNRs. Comet SW3 could be a moderately strong
radar target at Goldstone, and if we're lucky, we may be able to resolve the nucleus with
coarse-resolution ranging. Alternatively, it could be weak, but in any event, we should be able
to detect it.
The approach by Schwassmann-Wachmann 3 will be the closest by any comet since
comet Sugano-Saigusa-Fujikawa approached within 0.063 AU in June, 1983.
Orbital and Physical Characteristics: Fragment C
orbit type Jupiter-family periodic comet
semimajor axis 3.063 AU
eccentricity 0.693
inclination 11.4°
perihelion distance 0.939 AU
aphelion distance 5.186 AU
orbital period 5.360 years
diameter ~1 km (Z. Sekanina, pers. comm.)
rotation period unknown
pole direction unknown
lightcurve amplitude unknown
Orbital parameters for fragment B are similar.
Last updated: 2006 May 03
Discovery
SNR Calculation
Goldstone Track Assignments
Uncertainties
Setups
--------------------------------------------------------------------------------
Discovery
SEE ABOVE FOR A BRIEF DESCRIPTION OF THE COMET'S DISCOVERY
--------------------------------------------------------------------------------
SNR Calculation
SNR estimates below are for the nucleus of fragment C only; echoes from the comae may be much
stronger or much weaker.
Fragment C
Assumptions
Diameter: 1 km (Zdenek Sekanina, pers. comm.)
Period: 4 h (standard guess for near-Earth asteroids)
Radar albedo: 0.1 (probably an overestimate)
------------GOLDSTONE---------- -------------ARECIBO-----------
Max Max
Dat Run UTC Dat Run UTC
Date RA Decl Delta Runs SNR SNR Window Runs SNR SNR Window
2006 4 22 234 27 0.194 93 2 0 3:53-15:00 20 42 10 4:54- 7:24
2006 4 23 236 28 0.186 97 3 0 3:53-15:00 21 50 12 4:54- 7:24
2006 4 24 237 28 0.178 101 3 0 3:53-15:05 21 59 14 5:00- 7:24
2006 4 25 239 29 0.170 105 4 0 3:53-15:05 22 70 16 5:00- 7:24
2006 4 26 240 29 0.163 110 4 0 4:00-15:11 22 82 19 5:05- 7:24
2006 4 27 242 30 0.155 114 5 1 4:00-15:18 23 99 22 5:12- 7:24
2006 4 28 244 31 0.147 120 6 1 4:00-15:24 23 120 27 5:17- 7:30
2006 4 29 246 31 0.140 125 8 1 4:05-15:30 24 140 32 5:24- 7:30
2006 4 30 249 32 0.133 131 9 1 4:12-15:35 24 170 38 5:30- 7:35
2006 5 1 251 32 0.126 137 12 1 4:17-15:48 25 210 46 5:42- 7:42
2006 5 2 255 33 0.119 177 16 1 4:24-15:54 31 270 55 5:47- 7:47
2006 5 3 258 33 0.113 187 20 2 4:30-16:06 31 330 67 6:00- 7:54
2006 5 4 262 33 0.107 197 25 2 4:42-16:18 32 400 81 6:17- 8:05
2006 5 5 266 34 0.101 207 31 2 4:54-16:36 33 480 100 6:30- 8:18
2006 5 6 271 34 0.096 218 38 3 5:12-16:48 35 590 120 6:47- 8:35
2006 5 7 277 34 0.091 228 46 3 5:30-17:06 37 730 140 7:05- 8:54
2006 5 8 283 33 0.087 237 55 4 5:47-17:23 39 900 170 7:17- 9:11
2006 5 9 289 32 0.084 244 65 5 6:12-17:41 43 1100 190 7:35- 9:35
2006 5 10 296 31 0.081 248 73 5 6:35-18:06 47 1300 212 7:54-10:05
2006 5 11 302 30 0.080 250 79 6 7:05-18:23 51 1500 230 8:11-10:35
2006 5 12 309 28 0.079 248 82 6 7:35-18:41 55 1700 240 8:30-11:00
2006 5 13 316 25 0.079 243 81 6 8:00-18:53 57 1700 240 8:54-11:24
2006 5 14 322 23 0.080 236 77 6 8:30-19:11 58 1600 230 9:11-11:48
2006 5 15 328 20 0.082 226 69 5 8:54-19:23 56 1500 210 9:30-12:11
2006 5 16 333 17 0.084 214 60 5 9:18-19:30 54 1300 190 9:48-12:24
2006 5 17 338 14 0.088 202 51 4 9:41-19:41 52 1100 160 10:00-12:41
2006 5 18 342 12 0.092 190 42 3 10:00-19:48 48 900 140 10:18-12:48
2006 5 19 346 10 0.097 178 34 3 10:18-19:48 43 710 120 10:35-12:54
2006 5 20 349 7 0.102 166 27 2 10:35-19:53 38 550 96 10:48-13:00
2006 5 21 352 5 0.108 155 22 2 10:48-19:53 33 420 80 11:05-13:00
2006 5 22 355 4 0.114 145 17 2 11:00-20:00 29 310 66 11:18-13:00
2006 5 23 357 2 0.120 136 14 1 11:11-20:00 24 210 50 11:30-13:00
2006 5 24 360 1 0.127 104 10 1 11:24-20:00 15 130 37 11:48-12:54
2006 5 25 2 -1 0.134 99 8 1 11:30-20:00 11 82 26 12:00-12:48
Notes:
1. Arecibo SNRs assumed that both klystrons are available
2. SNRs are estimates for echoes from the nucleus of fragment C, which is thought to be the
largest.
3. Fragment E will approach within 0.051 AU on May 18, when it could be a strong target.
However, it has not yet been recovered.
--------------------------------------------------------------------------------
Track Assignments
Goldstone tracks
UT UT PST AST Duration Delta
DOY Date Fragment TX Window TX Window TX Window (hh:mm) (AU)
--- ---- -------- --------- --------- --------- ------- -----
129 May 09 B 0745-1430 0045-0730 0345-1030 6:45 0.078
C 0745-1430 0045-0730 0345-1030 6:45 0.082
132 May 12 B 0745-1430 0045-0730 0345-1030 6:45 0.068 Overlaps Arecibo
C 0745-1430 0045-0730 0345-1030 6:45 0.079 Overlaps Arecibo
134 May 14 B 1045-1835 0345-1135 0645-1435 7:50 0.067 Overlaps Arecibo
C 1045-1835 0345-1135 0645-1435 7:50 0.081 Overlaps Arecibo
141 May 21 B 1035-1840 0335-1140 0635-1440 8:05 0.091 Overlaps Arecibo
C 1045-1840 0345-1140 0645-1440 7:55 0.111 Overlaps Arecibo
E 1025-1840 0325-1140 0625-1440 8:15 0.060 This fragment has not been recovered
143 May 23 B 1130-1610 0430-0910 0730-1210 4:40 0.097 Overlaps Arecibo
C 1130-1610 0430-0910 0730-1210 4:40 0.124 Overlaps Arecibo
E 1130-1610 0430-0910 0730-1210 4:40 0.070 This fragment has not been recovered
Arecibo tracks (proposal R2183, Mike Nolan, John Harmon, et al.)
120 Apr 30 B 0502-0645 2202-2345 0102-0245 1:43 0.136
C 0529-0737 2229-0037 0129-0337 2:08 0.131
121 May 01 B 0512-0644 2212-2344 0112-0244 2:32 0.128
C 0538-0743 2238-0043 0138-0343 2:05 0.124
126 May 06 C 0648-0839 2348-0139 0248-0439 1:51 0.094
127 May 07 C 0705-0859 0005-0159 0305-0459 1:54 0.090
131 May 11 C 0818-1045 0118-0345 0418-0645 0.079
132 May 12 C 0836-1113 0136-0413 0436-0713 0.079
133 May 13 C 0855-1138 0155-0438 0455-0738 0.079
B 0856-1020 0156-0320 0456-0620 0.067
134 May 14 B 0906-1107 0206-0407 0506-0707 0.067
C 0913-1200 0213-0500 0513-0800 0.080
135 May 15 B 0921-1145 0221-0445 0521-0745 0.068
C 0931-1219 0231-0519 0531-0819 0.083
136 May 16 B 0936-1216 0236-0516 0536-0816 0.069
C 0949-1234 0249-0534 0549-0834 0.086
137 May 17 B 0953-1239 0253-0539 0553-0839 0.072
C 1006-1245 0306-0545 0606-0845 0.090
140 May 20 B 1041-1316 0341-0616 0641-0919 0.085
C 1054-1302 0354-0602 0654-0902 0.105
141 May 21 B 1056-1321 0356-0621 0556-0921 0.090
C 1108-1303 0408-0603 0708-0903 0.111
142 May 22 B 1110-1322 0410-0622 0710-0922 0.096
C 1123-1301 0423-0601 0723-0901 0.117
--------------------------------------------------------------------------------
Uncertainties
FRAGMENT C
From Jon Giorgini, 2006 May 02:
With 1393 optical observations (2006-Jan-2 to 2006-Apr-26),
73P-C solution #30 was computed. Current apparition data only.
Formal 3-sigma X-band uncertainties are shown below. Because
it's an active comet with unpredicted outgassing, actual
errors could exceed these statistical bounds.
Date__(UT)__HR:MN POS_3sigma DOP_X-sig RT_delay-sig
2006-May-08 00:00 4.11606310 2.65 0.003023
2006-May-09 00:00 4.80625205 2.08 0.002862
2006-May-10 00:00 5.50859628 1.64 0.002676
2006-May-11 00:00 6.17635146 1.56 0.002466
2006-May-12 00:00 6.75694142 1.92 0.002239
2006-May-13 00:00 7.20307124 2.54 0.002003
2006-May-14 00:00 7.48422503 3.24 0.001771
2006-May-15 00:00 7.59327890 3.92 0.001560
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
FRAGMENT B
With 876 optical obs (2006-Jan-6 to 2006-Apr-25, current apparition
only), 73P-B solution #18 was computed.
Formal 3-sigma X-band uncertainties are shown below. Because
it's an active comet with unpredicted outgassing, actual
errors could exceed these statistical bounds.
Date__(UT)__HR:MN POS_3sigma DOP_X-sig RT_delay-sig
2006-May-08 00:00 5.48536734 5.87 0.004857
2006-May-09 00:00 6.65479854 5.05 0.004647
2006-May-10 00:00 7.98133660 4.13 0.004391
2006-May-11 00:00 9.41810337 3.15 0.004081
2006-May-12 00:00 10.8756076 2.23 0.003714
2006-May-13 00:00 12.2244113 1.78 0.003295
2006-May-14 00:00 13.3183177 2.25 0.002839
2006-May-15 00:00 14.0353993 3.28 0.002375
--------------------------------------------------------------------------------
Setups
Plans for the May 9 track
-------------------------
Fragment B: We will start with solution 18.
Fragment C: We will start with solution 30.
Our plans for the first track depend heavily on results obtained during the first few tracks at Arecibo.
Previous radar observations of comets have revealed narrowband echoes from
the nucleus, broadband echoes from the coma, and in some cases, both. We do not yet know what to expect
from this comet, so we'll rely on early Arecibo results to guide our plans. We're going to utilize the
Arecibo echo bandwidths to plan our CW observing setup.
Regardless of the Arecibo results, we'll start with CW observations.
The CW setup below is a placeholder; we'll update it after the first detection at Arecibo.
CW setup
--------
TX polarization RCP
RCV polarization LCP
Frequencies: 2
Dwell: 30 seconds
Bandwidth: 40000 Hz
Sampling interval: 250 x 0.1 usec
VME FFT for PSD files: 2048 for 19.53-Hz resolution
Possible ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
FFT 64
CLT 2 (VME)
ncoh 1
bandwidth 787.4 Hz
resolution 12.30 Hz
TXOFF +100 Hz -> echo will be centered at +8.1 bins or in bin 32 + 8.1 = 40
---------------------------------------------------------------------------
127 x 64 11-usec single sample, 11.2-Hz resolution.
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 2 (VME)
ncoh 1
bandwidth 715.8 Hz
resolution 11.18 Hz
TXOFF +100 Hz --> echo will be centered at +8.9 bins or in bin 32 + 8.9 = 41
-------------------------------------------------------------------------
127 x 64 7-usec single sample
------------------------------
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT ??
ncoh 1
bandwidth 1124.9 Hz
resolution 17.6 Hz
TXOFF +60 -> echo would be centered at +3.4 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 1-usec single sample
------------------------------
baud 1 usec
code 127
gates 127
PRP 127
FFT 64
CLT 4
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +100 -> echo would be centered at +12.2 bins or in bin 32 + 12.2 = 44
-------------------------------------------------------------------------------
0.125-usec ranging (left over from the 1992 UY4 observations in August, 2005)
------------------
setup JX1XS001 revised
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 984
bandwidth 64.016384 Hz
resolution 1.000256 Hz
TXOFF We used 10 Hz, placing COM in cell 32+10=42
Henceforth use 15 Hz, to put COM in 32+15=47
incoh sums 4 looks=> 8 sec/record => expect records per run ~ RTT/8
PFS CLT gate 21
_____________________________________________________________________
POSSIBLE RANGING SETUPS: (code=127, FFT=64, single-pol'n)
These are from JX, w/ max-band (min-acc) options from Ray Jurgens.
Currently configured for 5-sec records.
_______________________________________________________________________
Setup Baud RP 1-acc 1-acc
usec m usec band res acc band res
_______________________________________________________________________
JX1XS110 11.000 1650 1397.0 715.8 11.2 2 358 5.6
JX1XS070 7.000 1050 889.0 1124.9 17.6 3 375 5.9
JX1XS020 2.000 300 254.0 3937.0 61.5 12 328 5.1
4 984 15.4
JX1XS010 1.000 150 127.0 7874.0 123.0 41 192 3.0
8 984 15.4
JX1XS005 0.500 75 63.5 15748.0 246.1 123 128 2.0
15 1050 16.4
JX1XS002 0.250 37.5 31.75 31496.1 492.1 492 64 1.0
30 1050 16.4
JX1XS001 0.125 18.75 15.875 62992.1 984.3 1970 32 0.5
60 1050 16.4
____________________________________________________________________
--------------------------------------------------------------------------------
Instructions
NOTE: Data should be moved to the appropriate subdirectories in:
stealth:/export/data0/rosema/73p/fragmentB/raw/
stealth:/export/data0/rosema/73p/fragmentC/raw/
73P/Schwassmann-Wachmann 3 POINTING:
OSOD and predicts are at Goldstone on stealth:
/export/data2/osod/ops/73p-c/PRDX.OUT.s30 FRAGMENT C
/PUNCH.OUT.s30 FRAGMENT C
/EPH.OUT.s30 FRAGMENT C
and
/export/data2/osod/ops/73p-b/PRDX.OUT.s18 FRAGMENT B
/PUNCH.OUT.s18 FRAGMENT B
/EPH.OUT.s18 FRAGMENT B
and have been copied to:
/export/data0/rosema/73p/fragmentC/support/
and
/export/data0/rosema/73p/fragmentB/support/
POINTING
FRAGMENT C
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2006 05 09 129 070000 290.8092 32.0693 A 82.9 30
2006 05 09 129 080000 291.0804 32.0255 A 82.8
2006 05 09 129 090000 291.3503 31.9804 A 82.7
2006 05 09 129 100000 291.6194 31.9341 A 82.6
2006 05 09 129 110000 291.8879 31.8863 A -0.0061 -0.0011 82.5
2006 05 09 129 120000 292.1562 31.8370 A 82.4
2006 05 09 129 130000 292.4249 31.7861 A 82.2
2006 05 09 129 140000 292.6944 31.7337 A 82.1
2006 05 09 129 150000 292.9652 31.6797 A 82.0
FRAGMENT B
2006 05 09 129 070000 275.7343 40.6490 A 78.7 18
2006 05 09 129 080000 276.0175 40.6513 A 78.6
2006 05 09 129 090000 276.3004 40.6521 A 78.4
2006 05 09 129 100000 276.5834 40.6513 A 78.2
2006 05 09 129 110000 276.8670 40.6487 A -0.0062 -0.0001 78.0
2006 05 09 129 120000 277.1519 40.6442 A 77.8
2006 05 09 129 130000 277.4385 40.6378 A 77.6
2006 05 09 129 140000 277.7274 40.6297 A 77.5
2006 05 09 129 150000 278.0190 40.6199 A 77.3
--------------------------------------------------------------------------------
FRAGMENT C PRDX.OUT.s30
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2006 MAY 09 07:40 82.8531587206 289783.110 294.1054 32.0402 290.990 36.130
2006 MAY 09 07:50 82.8328773081 288908.095 296.5671 32.0328 291.035 38.054
2006 MAY 09 08:00 82.8126582920 288002.811 299.0288 32.0255 291.080 39.988
2006 MAY 09 08:10 82.7925037749 287067.913 301.4906 32.0180 291.125 41.930
2006 MAY 09 08:20 82.7724158017 286104.106 303.9524 32.0106 291.170 43.881
2006 MAY 09 08:30 82.7523963788 285112.151 306.4142 32.0031 291.215 45.840
2006 MAY 09 08:40 82.7324474482 284092.859 308.8761 31.9956 291.260 47.806
2006 MAY 09 08:50 82.7125708959 283047.092 311.3380 31.9880 291.305 49.779
2006 MAY 09 09:00 82.6927685463 281975.758 313.7999 31.9804 291.350 51.758
2006 MAY 09 09:10 82.6730421582 280879.815 316.2619 31.9728 291.395 53.743
2006 MAY 09 09:20 82.6533934218 279760.264 318.7238 31.9652 291.440 55.732
2006 MAY 09 09:30 82.6338239556 278618.148 321.1858 31.9574 291.485 57.726
2006 MAY 09 09:40 82.6143353035 277454.554 323.6479 31.9497 291.530 59.723
2006 MAY 09 09:50 82.5949289318 276270.607 326.1099 31.9419 291.575 61.724
2006 MAY 09 10:00 82.5756062266 275067.468 328.5719 31.9341 291.619 63.727
2006 MAY 09 10:10 82.5563684916 273846.335 331.0340 31.9263 291.664 65.730
2006 MAY 09 10:20 82.5372169450 272608.436 333.4961 31.9184 291.709 67.734
2006 MAY 09 10:30 82.5181527182 271355.033 335.9582 31.9104 291.754 69.737
2006 MAY 09 10:40 82.4991768496 270087.414 338.4203 31.9024 291.798 71.736
2006 MAY 09 10:50 82.4802902964 268806.893 340.8824 31.8944 291.843 73.729
2006 MAY 09 11:00 82.4614939097 267514.807 343.3445 31.8863 291.888 75.711
2006 MAY 09 11:10 82.4427884591 266212.516 345.8066 31.8782 291.933 77.677
2006 MAY 09 11:20 82.4241746052 264901.396 348.2688 31.8701 291.977 79.615
2006 MAY 09 11:30 82.4056529216 263582.839 350.7309 31.8619 292.022 81.505
2006 MAY 09 11:40 82.3872238803 262258.254 353.1930 31.8536 292.067 83.304
2006 MAY 09 11:50 82.3688878542 260929.055 355.6551 31.8453 292.111 84.911
2006 MAY 09 12:00 82.3506451135 259596.668 358.1172 31.8370 292.156 86.084
2006 MAY 09 12:10 82.3324958382 258262.524 0.5793 31.8286 292.201 86.371
2006 MAY 09 12:20 82.3144400947 256928.055 3.0414 31.8202 292.246 85.594
2006 MAY 09 12:30 82.2964778587 255594.696 5.5035 31.8118 292.290 84.165
2006 MAY 09 12:40 82.2786090024 254263.876 7.9655 31.8033 292.335 82.445
2006 MAY 09 12:50 82.2608332978 252937.021 10.4276 31.7947 292.380 80.594
2006 MAY 09 13:00 82.2431504136 251615.551 12.8896 31.7861 292.425 78.675
2006 MAY 09 13:10 82.2255599301 250300.870 15.3516 31.7775 292.470 76.719
2006 MAY 09 13:20 82.2080613152 248994.376 17.8136 31.7688 292.515 74.742
2006 MAY 09 13:30 82.1906539504 247697.445 20.2755 31.7601 292.560 72.751
2006 MAY 09 13:40 82.1733371174 246411.440 22.7374 31.7513 292.604 70.751
2006 MAY 09 13:50 82.1561100032 245137.699 25.1993 31.7425 292.649 68.746
2006 MAY 09 14:00 82.1389717019 243877.541 27.6612 31.7337 292.694 66.739
2006 MAY 09 14:10 82.1219212159 242632.256 30.1230 31.7248 292.739 64.730
2006 MAY 09 14:20 82.1049574583 241403.108 32.5848 31.7158 292.785 62.722
2006 MAY 09 14:30 82.0880792511 240191.329 35.0465 31.7069 292.830 60.715
FRAGMENT B PRDX.OUT.s18
2006 MAY 09 07:40 78.6192786028 451336.559 309.1723 40.6507 275.923 50.186
2006 MAY 09 07:50 78.5876739717 450445.025 311.6320 40.6510 275.970 52.030
2006 MAY 09 08:00 78.5561326341 449530.738 314.0917 40.6513 276.017 53.880
2006 MAY 09 08:10 78.5246561542 448594.564 316.5514 40.6515 276.065 55.735
2006 MAY 09 08:20 78.4932460346 447637.406 319.0111 40.6517 276.112 57.595
2006 MAY 09 08:30 78.4619037141 446660.207 321.4708 40.6519 276.159 59.457
2006 MAY 09 08:40 78.4306305620 445663.943 323.9305 40.6520 276.206 61.322
2006 MAY 09 08:50 78.3994278808 444649.628 326.3902 40.6521 276.253 63.188
2006 MAY 09 09:00 78.3682968986 443618.306 328.8499 40.6521 276.300 65.054
2006 MAY 09 09:10 78.3372387701 442571.050 331.3096 40.6521 276.348 66.918
2006 MAY 09 09:20 78.3062545735 441508.965 333.7693 40.6520 276.395 68.777
2006 MAY 09 09:30 78.2753453090 440433.178 336.2290 40.6519 276.442 70.630
2006 MAY 09 09:40 78.2445118966 439344.844 338.6886 40.6518 276.489 72.472
2006 MAY 09 09:50 78.2137551747 438245.138 341.1483 40.6516 276.536 74.298
2006 MAY 09 10:00 78.1830758987 437135.256 343.6079 40.6513 276.583 76.100
2006 MAY 09 10:10 78.1524747394 436016.410 346.0676 40.6510 276.631 77.865
2006 MAY 09 10:20 78.1219522822 434889.829 348.5272 40.6506 276.678 79.575
2006 MAY 09 10:30 78.0915090257 433756.755 350.9868 40.6502 276.725 81.194
2006 MAY 09 10:40 78.0611453821 432618.442 353.4463 40.6497 276.772 82.661
2006 MAY 09 10:50 78.0308616729 431476.149 355.9059 40.6492 276.820 83.863
2006 MAY 09 11:00 78.0006581334 430331.145 358.3654 40.6487 276.867 84.621
2006 MAY 09 11:10 77.9705349090 429184.702 0.8248 40.6480 276.914 84.738
2006 MAY 09 11:20 77.9404920568 428038.092 3.2843 40.6474 276.962 84.174
2006 MAY 09 11:30 77.9105295424 426892.588 5.7436 40.6466 277.009 83.095
2006 MAY 09 11:40 77.8806472445 425749.459 8.2030 40.6459 277.057 81.701
2006 MAY 09 11:50 77.8508449523 424609.969 10.6623 40.6450 277.104 80.123
2006 MAY 09 12:00 77.8211223670 423475.374 13.1216 40.6442 277.152 78.439
2006 MAY 09 12:10 77.7914791013 422346.921 15.5808 40.6432 277.200 76.689
2006 MAY 09 12:20 77.7619146812 421225.842 18.0399 40.6422 277.247 74.898
2006 MAY 09 12:30 77.7324285472 420113.356 20.4991 40.6412 277.295 73.079
2006 MAY 09 12:40 77.7030200557 419010.666 22.9581 40.6401 277.343 71.242
2006 MAY 09 12:50 77.6736884768 417918.955 25.4171 40.6390 277.391 69.392
2006 MAY 09 13:00 77.6444330017 416839.383 27.8760 40.6378 277.438 67.535
2006 MAY 09 13:10 77.6152527379 415773.089 30.3349 40.6366 277.486 65.673
2006 MAY 09 13:20 77.5861467171 414721.187 32.7937 40.6353 277.535 63.808
2006 MAY 09 13:30 77.5571138908 413684.759 35.2524 40.6339 277.583 61.942
2006 MAY 09 13:40 77.5281531387 412664.863 37.7111 40.6326 277.631 60.077
2006 MAY 09 13:50 77.4992632653 411662.523 40.1697 40.6311 277.679 58.213
2006 MAY 09 14:00 77.4704430049 410678.727 42.6282 40.6297 277.727 56.353
2006 MAY 09 14:10 77.4416910240 409714.433 45.0866 40.6281 277.776 54.497
2006 MAY 09 14:20 77.4130059242 408770.558 47.5450 40.6266 277.824 52.645
2006 MAY 09 14:30 77.3843862415 407847.982 50.0033 40.6250 277.873 50.799
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GOLDSTONE MASTERLOG
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RCV
file setup runs start -stop osod OFFSET TX Poln
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RADAR ASTROMETRY
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Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 300-233 | FAX: (818) 354-9476
Jet Propulsion Laboratory | email: lance@reason.jpl.nasa.gov
Pasadena, CA 91109-8099 | Plan: To live long and prosper
[link to echo.jpl.nasa.gov]
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Asteroid Radar Astronomy |
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Pollyannuh
User ID: 46877
5/6/2006 12:58 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
I'm liking Dr. Lance A. M. Benner's plan at the end of this report....
"To live long and prosper."
 |
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Halcyon Dayz
User ID: 84549
5/6/2006 5:00 AM
 | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
They plan to observe fragments B and C with RADAR.
Using dishes in California and Porto Rico.
This should give accurate measurements of
speed and vector, as well as rotation.
RADAR does this a lot better then optical
observation.
They also hope to image the nuclei.
"Previous radar observations of comets have revealed narrowband echoes from
the nucleus, broadband echoes from the coma, and in some cases, both.
We do not yet know what to expect from this comet..."
Means exactly what it says.
SNR means signal-to-noise ratio. [link to en.wikipedia.org]
An idea is not responsible for the people who believe in it. - Don Marquis
To defy the authority of empirical evidence is to disqualify oneself as someone worthy of critical engagement in a dialogue. - Tenzin Gyatso
Entia non sunt multiplicanda praeter necessitatem - William of Ockham
The truth maybe out there, but lies are inside your head - Terry Pratchett
HALCYON DAYS STOP BEING A DIPSHIT ALL YOUR LIFE YOU MORON - Anonymous Coward |
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Pollyannuh
User ID: 46877
5/6/2006 11:21 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
Halcyon, if they don't know what to expect, how can we make our preparations?
Then, again, we won't be told anything, anyway.
It'll be 15 foot above us and they'll claim ignorance.
 |
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bigbamabutt
User ID: 15505
5/6/2006 11:29 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
"Formal 3-sigma X-band uncertainties are shown below. Because
it's an active comet with unpredicted outgassing, actual
errors could exceed these statistical bounds."
In essence NASA can't update. |
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Pollyannuh
User ID: 46877
5/6/2006 11:34 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
Well, there ya go, bigbamabutt.
The fragments will be 15 foot above us and even NASA won't know what's about to hit them/us.
 |
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Sinanju
User ID: 88779
5/6/2006 11:50 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
NASA is a waste of money.
Want to colonise the stars? Want to protect the earth from exterior threats?
Contract it out to Halliburton. They will overcharge us but at least they will fucking do SOMETHING. |
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Anonymous Coward
User ID: 90091
5/6/2006 12:02 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
You are expecting too much from NASA (and from everyone else, for that matter). The fact is that us humans don't know as much about this universe as we like to think we know.
People are deceived because they ask daddy (NASA, the government, their church etc) and he doesn't give them answers because we all humans really don't know! |
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Anonymous Coward
User ID: 84505
5/6/2006 12:02 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
i thought they already claimed to know that "nothing will impact the earth"
which is it? |
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Anonymous Coward
User ID: 84505
5/6/2006 12:05 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
and then the debunkers castigate us for not trusting NASA
i guess you can't win |
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Anonymous Coward
User ID: 90091
5/6/2006 12:07 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
You are thinking about an institution as if it were a person talking to you. If the information contradicts itself sometimes, you think of it as if it were someone being inconsistent and even lying.
That is a childish way of thinking. You must be able to distinguish different levels, kinds and contexts in the information that reaches you! |
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Sinanju
User ID: 88779
5/6/2006 12:08 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
"You are expecting too much from NASA"
Exxon-Mobil could build a spaceship, launch it and set up a base on mars in under FIVE months... that's FIVE with an 'IVE'.
It takes three months to get there.
NASA wants to take a decade to flyby the moon. Gubmint incompetance. |
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Anonymous Coward
User ID: 90091
5/6/2006 12:10 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
In the science-fiction books you read and the films you watch everything is easy, isn't it? |
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Anonymous Coward
User ID: 90104
5/6/2006 12:10 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
we are on are own .
always have been
have food and water and someway to cook . Guns and ammo always a good idea |
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Anonymous Coward
User ID: 84505
5/6/2006 12:12 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
i guess we treat NASA like debunkers treat posters on glp
everything is lumped together into one big pile of lunacy |
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Anonymous Coward
User ID: 42888
5/6/2006 12:13 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
During May, 2006 fragments B, C, and most of the others will approach within 0.079 AU.
Fragment E was last observed in December, 2000. It is predicted to approach within 0.051 AU
several days after the other fragments, when we hope to observe it, presuming, of course,
that it still exists.
from ops link in the first post |
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Sinanju
User ID: 88779
5/6/2006 12:19 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
"In the science-fiction books you read and the films you watch everything is easy, isn't it?"
NOT fiction.
Exxon-Mobil IS conducting experiments on 3 month suspended animation.
WHY?
Why 3 months of suspended animation?
At our current travel speed... that is how long it would take to reach MARS.
Ponder. |
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Anonymous Coward
User ID: 84505
5/6/2006 12:21 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
why are normal citizens mocked for not knowing
but, NASA is given a free pass? |
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floydian slip
User ID: 42888
5/6/2006 12:21 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
because thet are now in the gravity racket, and if you dont pay your gravity bill it will be turned off for 3 months |
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Anonymous Coward
User ID: 90048
5/6/2006 12:24 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
 |
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molesworth
User ID: 89548
5/6/2006 12:28 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
You're taking the "don't know what to expect" remark completely out of context. They're discussing detailed planning for radar observations, and need to be able to pin down exact times and positions.
Read the whole paragraph, and try to see it in the context it was written :-
"Our plans for the first track depend heavily on results obtained during the first few tracks at Arecibo. Previous radar observations of comets have revealed narrowband echoes from the nucleus, broadband echoes from the coma, and in some cases, both. We do not yet know what to expect from this comet, so we'll rely on early Arecibo results to guide our plans. We're going to utilize the Arecibo echo bandwidths to plan our CW observing setup."
In other words, they can't make the detailed plans until the other results are in, telling them when and where to point... |
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Anonymous Coward
User ID: 62398
5/6/2006 12:31 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
NASA - The comet will strike the Atlantic at 9.30am!
MOLESWORTH - Yes, but when they say ''strike'', they actually mean.............
Only kidding Mole! I can see what you're getting at! |
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Anonymous Coward
User ID: 7499
5/6/2006 12:39 PM | |
Anonymous Coward
User ID: 90091
5/6/2006 12:52 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
I can see that most people here are not interested in truth, only in bashing and exercising their "wise" scepticism... |
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Anonymous Coward
User ID: 80246
5/6/2006 1:08 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
molesworth
User ID: 89548
5/6/2006 12:28 PM
Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring!
You're taking the "don't know what to expect" remark completely out of context. They're discussing detailed planning for radar observations, and need to be able to pin down exact times and positions.
Read the whole paragraph, and try to see it in the context it was written :-
"Our plans for the first track depend heavily on results obtained during the first few tracks at Arecibo. Previous radar observations of comets have revealed narrowband echoes from the nucleus, broadband echoes from the coma, and in some cases, both. We do not yet know what to expect from this comet, so we'll rely on early Arecibo results to guide our plans. We're going to utilize the Arecibo echo bandwidths to plan our CW observing setup."
In other words, they can't make the detailed plans until the other results are in, telling them when and where to point...
I disagree. This appears to illustrste an uncertainty as to density and composition which could produce different types of radar returns. This could have further ramifications. I could be wrong, though. |
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Anonymous Coward
User ID: 80246
5/6/2006 1:08 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
*illustrate |
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Anonymous Coward
User ID: 89430
5/6/2006 1:18 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
Plausible deniability
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Plausible deniability also Deniability is the term given to the creation of loose and informal chains of command in government, which allow controversial instructions given by high-ranking officials to be denied if they become public.
In addition, in politics and espionage, deniability is the ability of a powerful player or actor to avoid blowback by secretly arranging for an action to be taken on their behalf by a third party.
The necessary act is farmed out or delegated to a third party ostensibly unconnected with the major player. This can take the form of a private person or mercenary being hired to carry out a task, or a government or agency being asked or compelled to do you a quiet favor. 
[link to en.wikipedia.org] |
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Anonymous Coward
User ID: 84505
5/6/2006 1:53 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
observation is related to trajectory
if they can't find it
that means they dont' know where it is or where it's going |
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Anonymous Coward
User ID: 84505
5/7/2006 9:22 AM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
so, do they know more today? |
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Anonymous Coward
User ID: 90532
5/7/2006 4:08 PM | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
 |
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Gewgaw
User ID: 83507
5/7/2006 4:19 PM
 | | Re: NASA "We do not yet know what to expect from this comet..." Well, THAT's reasurring! | Quote |
Since they do not know what to expect, and more fragments appear constantly, how can they say none will hit us? How do they know that an as-yet unformed fragment will not veer off toward Earth? |
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