I agree with Harro that a more detailed account of this observation would be valuable - I am trying to get one. However, I am not sure that I agree fully with Harro's calculations. While I believe Harro is correct for an observer on the ground in Maseru, Lesotho, I suspect that he has not allowed for the 33,000 ft (not 11,000 ft) altitude of the observer. At such a height, the horizon is depressed below the horizontal by almost exactly 3 degrees - or put another way, the horizon is at an angular zenith distance of 93 degrees. At a range of 856 km and a height of 87 degrees, I get a zenith distance for the object of 88.7 degrees (observer at 33,000 ft), corresponding to an angle above the apparent horizon of 4.3 degrees. Given that the line of sight would be through relatively clean high-altitude air, it does not seem too surprising that the decay would be visible. Also, again because of the high vantage point, I suspect that it could have been in view for 3 minutes or more as it tracked southwards from the vicinity of Zumbo where Zambia, Zimbabwe and Mozambique meet on the Zambezi. This would lie in the NNE as seen from Maseru and the angular velocity would be surprisingly low at that range. Alan -- Alan Pickup / COSPAR 2707: 55d53m48.7s N 3d11m51.2s W 156m asl Edinburgh / SatEvo & elsets: http://www.wingar.demon.co.uk/satevo/ Scotland / Decay Watch: http://www.wingar.demon.co.uk/satevo/dkwatch/ ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Fri Oct 13 2000 - 13:58:38 PDT