Frequency of Bright Close Approaches?

Ed Cannon (ecannon@mail.utexas.edu)
Sat, 15 Feb 1997 04:43:58 -0600

How frequent are coincidental (unplanned) close approaches that are visible 
without magnification?

On Feb. 11 (12:12:57-58 UT), just a half minute or so before a very nice 
STS-82 pass on its second orbit, I observed the following visual close 
approach:

>   30.308  97.728  500.   Hyde Park, Austin, TX    2000  3.5 23 F F T F F
> 
> ***  1997 Feb  11  Tue morning  *** Times are AM CST  ***  1859  631
> 
>  H  M  S  Tim Al Azi C Dir  Mag Dys F  Hgt Shd  Rng  EW Phs  R A   Dec
> 
> 10135 Cosmos 925 Rk  77 61B   3.8 2.6      13 4.0   3.5 
>  6 12 57   .0 46 328   132  2.8   2 0  452 193  606 2.2  52 1158  60.2
> 
> 23834 GPS Rk         96 19B                12       3.5 
>  6 12 58   .0 46 325    49  3.0   5 8  485 217  650 2.1  51 1153  58.8

The objects were 33 km. apart in height at the time, so it was just an 
apparent approach.  But they are fun anyway!  (The first one I saw was 
last Mother's Day from San Antonio, as I was showing my mom a bright 
satellite passing over -- and there came another one!)

Ed Cannon
Austin, Texas, USA
30.308N, 97.728W