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 email@example.com --- The archive has a search facility, and an e-mail message to firstname.lastname@example.org with Subject: archive and with body: egrep balloon latest/* will get you a list of all recent messages containing the word balloon. Obviously, you could search for spartan, iae, and other words you can think of. Another message specifying the message numbers will get you the messages themselves. Once you get some messages, you will probably see other words you might want to search for.