SOCRATES

Top 10 Conjunctions
by Minimum Range

Data current as of 2008 May 17 12:00 UTC

Computation Interval: Start = 2008 May 17 12:00:00.000, Stop = 2008 May 24 12:00:00.000
Computation Threshold: 5.0 km
Considering: 2,886 Primaries, 11,436 Secondaries (11,122 Conjunctions)

See notes at bottom of page for data field descriptions

 
Action NORAD
Catalog
Number		 Name Days
Since
Epoch		 Max
Probability		 Dilution
Threshold
(km)		 Min
Range
(km)		 Relative
Velocity
(km/sec)
Start
(UTC)		 TCA
(UTC)		 Stop
(UTC)
27846 AAU CUBESAT 4.349 4.038E-04 0.043 0.060 4.683
30049 FENGYUN 1C DEB 3.370 2008 May 19 21:26:51.102 2008 May 19 21:26:52.169 2008 May 19 21:26:53.237
19907 COSMOS 2013 4.389 5.627E-04 0.050 0.071 8.897
20238 SL-14 R/B 4.679 2008 May 20 20:27:22.234 2008 May 20 20:27:22.796 2008 May 20 20:27:23.358
11541 COSMOS 1133 6.463 5.244E-04 0.052 0.073 12.808
18794 SL-14 R/B 6.190 2008 May 22 09:49:47.630 2008 May 22 09:49:48.020 2008 May 22 09:49:48.410
08325 COSMOS 770 5.863 4.390E-04 0.063 0.089 14.021
20306 SL-14 R/B 6.018 2008 May 21 22:58:04.747 2008 May 21 22:58:05.103 2008 May 21 22:58:05.460
24872 IRIDIUM 18 7.356 1.432E-03 0.066 0.094 14.906
26323 CZ-4B DEB 6.952 2008 May 23 10:48:52.246 2008 May 23 10:48:52.581 2008 May 23 10:48:52.916
Action NORAD
Catalog
Number		 Name Days
Since
Epoch		 Max
Probability		 Dilution
Threshold
(km)		 Min
Range
(km)		 Relative
Velocity
(km/sec)
Start
(UTC)		 TCA
(UTC)		 Stop
(UTC)
07529 NOAA 4 1.695 8.626E-04 0.079 0.112 13.900
16268 COSMOS 1691 DEB 2.814 2008 May 18 20:38:16.440 2008 May 18 20:38:16.800 2008 May 18 20:38:17.159
16952 COSMOS 1777 3.403 2.700E-04 0.080 0.114 14.036
09040 DELTA 1 DEB 2.753 2008 May 19 22:42:46.028 2008 May 19 22:42:46.384 2008 May 19 22:42:46.741
09661 METEOR 2-2 4.791 9.285E-04 0.097 0.137 14.825
30552 FENGYUN 1C DEB 5.851 2008 May 21 20:07:46.513 2008 May 21 20:07:46.850 2008 May 21 20:07:47.187
18118 COSMOS 1857 1.574 5.111E-05 0.102 0.144 13.897
14881 THORAD DELTA 1 DEB 3.124 2008 May 18 18:33:58.774 2008 May 18 18:33:59.133 2008 May 18 18:33:59.493
27561 RUBIN-3 & SL-8 R/B 8.145 6.401E-05 0.107 0.152 14.185
20905 CZ-4 DEB 7.190 2008 May 24 09:15:47.800 2008 May 24 09:15:48.152 2008 May 24 09:15:48.505
 
Data Fields:
  • Action: The Analysis button links to a page which provides a capability to build an interactive 3-D STK/CAT (Conjunction Analysis Tools) scenario detailing the conjunction.
  • NORAD Catalog Number: NORAD Catalog Numbers of the two conjuncting objects.
  • Name: Common names of the two conjuncting objects.
  • Days Since Epoch: The number of days from the epoch of the NORAD two-line element set used to produce the prediction until the time of closest approach for the conjunction.
  • Max Probability: Given fixed spherical object radii and relative distance at the time of closest approach (TCA), the projected covariance ellipse is sized and oriented to produce the maximum probability. For these reports the ratio of major-to-minor axes of the projected covariance ellipse is set to one (AR=1, no orientation is necessary). If the combined object radius is greater than the relative distance, the maximum probability will be one; such occurrences are not addressed here.
  • Dilution Threshold (km): The standard deviation that produces the maximum probability defines the threshold of dilution. A smaller or larger standard deviation will produce a smaller probability. In the case of computing true probability with a smaller standard deviation, the data is of sufficient quality to associate low probability with low risk. For a larger standard deviation, this is not the case and the resulting true probability calculation becomes "diluted." If operating in this dilution region, the recommendation is to obtain better data and reassess the encounter. If time or resources do not permit, then the maximum probability should be used in place of the true probability.
  • Min Range (km): The distance between the two conjuncting objects at the time of closest approach.
  • Start (UTC): Time when the two conjuncting objects come within the computation threshold from each other.
  • TCA (UTC): Time of closest approach.
  • Stop (UTC): Time when the two conjuncting objects move beyond the computation threshold from each other.
  • Relative Velocity (km/sec): Relative velocity of the two conjuncting objects at the time of closest approach.
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Dr. T.S. Kelso [TS.Kelso@celestrak.com]
Last updated: 2008 May 17 13:51:27 UTC
Accessed 29,450 times since 2000 December 16
Current system time: 2008 May 17 18:18:41 UTC