SOCRATES

Top 10 Conjunctions
by Minimum Range

Data current as of 2009 Jan 07 02:00 UTC

Computation Interval: Start = 2009 Jan 07 00:00:00.000, Stop = 2009 Jan 14 00:00:00.000
Computation Threshold: 5.0 km
Considering: 2,937 Primaries, 11,758 Secondaries (11,710 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)
33399 SOYUZ-TMA 13 1.426 1.000E+00 0.000 0.000 0.000
33443 PROGRESS-M 1M 1.426 2009 Jan 07 00:00:00.000 2009 Jan 07 00:00:00.000 2009 Jan 14 00:00:00.000
15986 COSMOS 1677 1.326 1.556E-02 0.023 0.033 14.321
31803 FENGYUN 1C DEB 29.235 2009 Jan 07 20:45:42.865 2009 Jan 07 20:45:43.214 2009 Jan 07 20:45:43.564
27450 IRIDIUM 97 5.150 7.677E-03 0.029 0.041 14.825
30392 FENGYUN 1C DEB 5.270 2009 Jan 11 17:33:44.466 2009 Jan 11 17:33:44.803 2009 Jan 11 17:33:45.140
23465 FAISAT 6.340 1.049E-03 0.039 0.056 2.361
31555 FENGYUN 1C DEB 9.782 2009 Jan 13 00:31:21.932 2009 Jan 13 00:31:24.050 2009 Jan 13 00:31:26.168
21728 COSMOS 2157 4.152 3.551E-04 0.046 0.065 2.743
08143 THORAD DELTA 1 DEB 3.526 2009 Jan 10 01:12:08.286 2009 Jan 10 01:12:10.109 2009 Jan 10 01:12:11.932
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)
06787 OPS 8364 (DMSP 4) 2.722 1.272E-04 0.076 0.108 14.657
30485 FENGYUN 1C DEB 2.303 2009 Jan 08 07:23:01.061 2009 Jan 08 07:23:01.402 2009 Jan 08 07:23:01.743
25280 TRACE 1.316 1.243E-04 0.077 0.109 0.393
26759 CZ-4B DEB 2.746 2009 Jan 07 20:37:49.075 2009 Jan 07 20:38:01.792 2009 Jan 07 20:38:14.509
24950 IRIDIUM 31 2.052 2.146E-03 0.077 0.109 14.634
12792 SL-8 R/B 2.304 2009 Jan 08 11:47:46.582 2009 Jan 08 11:47:46.924 2009 Jan 08 11:47:47.265
28060 SERVIS 1 4.323 1.244E-04 0.077 0.109 4.779
30668 FENGYUN 1C DEB 3.396 2009 Jan 10 07:37:18.396 2009 Jan 10 07:37:19.442 2009 Jan 10 07:37:20.488
17973 COSMOS 1844 2.030 1.195E-04 0.078 0.111 8.138
29931 FENGYUN 1C DEB 2.762 2009 Jan 08 05:22:52.600 2009 Jan 08 05:22:53.214 2009 Jan 08 05:22:53.828
 
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: 2009 January 7 04:01:27 UTC
Accessed 33,678 times since 2000 December 16
Current system time: 2009 January 7 04:21:04 UTC