Top 10

Walter Nissen (dk058@cleveland.Freenet.Edu)
Mon, 1 Jul 1996 09:43:55 -0400

A correspondent, who has not authorized this quote, writes last week: 
> signed onto the SeeSat-L mailing list last month, ... do you 
> have any ... suggestions for "sure fire" satellites - ones predictably 
> bright enough to be seen with the naked eye, besides the space shuttle and 
> Mir?  Do you know if there is any sort of brightness ranking for satellites 
> anywhere?  - a sort of "Top 10" list? 
 
(One could dismiss this desire by adopting this attitude: 
          If you want to shoot fish in a barrel, there are many 
          astronomical objects which are predictably visible, 
          including Mercury, Pluto, comets, meteors.  If you 
          hunger a bit more for the hunt, satellites are more 
          suitable. 
I will not do so, but take note of the valid point.) 
 
As long-time subscribers to SeeSat-L already know, I have written 
repeatedly on this subject, here and on the Celestial BBS, but without 
ever actually being able to compile a Top 10 list.  I have warned against 
a) using old elsets, b) looking for radio dots, and c) programs which 
display the shadow ingress and egress improperly.  I've suggested that 
QuickSat deals quite successfully with each of these problems which 
commonly plague people still working toward their first hundred or first 
dozen satellites.  I've tried to characterize the causes of variability 
and unpredictability in satellite brightness.  I've produced a list of the 
brightest satellites I've seen.  (This list and QuickSat and all the 
previous messages are available from the archive.) 
 
Quite recently, I noted that Jay Respler and TS Kelso's VISUAL.TLE is a 
pretty good "Top 100" and suggested that people might make suggestions for 
a Top 10 list. 
 
Not too many did, and one of the thoughtful lists went in a slightly 
different direction. 
 
There are a number of problems with characterizing a Top 10.  A satellite 
which is occasionally very bright, but not consistently so, is not very 
suitable.  (Among others, the NOAAs sometimes reach mag -1).  Even the 
shuttle is not fully reliable.  A bright tumbler may be fine for a certain 
period of time, but then develop such a long period that it becomes 
troublesome.  You may like the Zenit-2's, but there are more than a dozen 
of them, not 10, all but one in essentially the same size orbit.  GRO is a 
very bright satellite but in such a low orbit at such a low inclination 
that many active observers have never seen it.  The 15.52 EORSATs are 
bright, but have short lifetimes, forcing frequent revisions in any list. 
Rocket bodies in low eccentric orbits have short lifetimes, but may be 
quite spectacular.  I had hoped that some genius would characterize all 
these factors and develop a great list. 
 
No such luck.  Here is a list which is not horrible: 
 
Mir 
shuttles 
 23931 
15.52 EORSATs 
 23596 
 23748 
Lacrosse 1 
Lacrosse 2 
UARS 
Resurs 1-3 r 
HST 
GRO 
C* 1220 
Lacrosse 2 r 
KH 11's & 12's 
 19625 
 22251 
 23728 
SeaSat 1 
14.13 Zenit-2's 
 16182 
 17590 
 17974 
 19120 
 19650 
 20625 
 22220 
 22285 
 22566 
 22803 
 23088 
 23405 
 23705 
EGP = Ajisai 
C* 1093 
C* 1703 
C* 925 
C* 1933 
C* 1953 
SROSS-C2 
DMSP F3 
NOSS 2-n's 
 20682 
 21799 
 96294 
USA 32 and 81 
 
Anybody want to try to sharpen it up?  Or shorten it?  Or rank them? 
 
Of course, even with a list, a poor pass from a listed object will not be 
as good as a good pass from a hundred or more also rans.  Which brings me 
back to QuickSat with Ted Molczan's file as input.  You have to adjust the 
magnitude and altitude limits to taste, and guess about discarding some 
highly overrated new objects, and expect a few clunkers making poor 
passes, but you get something within shouting distance of what you want. 
 
Cheers. 
 
Walter Nissen                   dk058@cleveland.freenet.edu 
 
--- 
 
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