> far as I could see it and was surprised how easy it was to tell that the > satellite was an object at great height because it faded away at such a > high altitude (unlike a plane which can be followed right to the > horizon). Since then, I have been observing satellites more frequently. > This is if the satellite happens to enter Earth's shadow (or turn/tumble so its brighness is reduced) If you can follow it close to the horizon, an airplane approaches zero angular velocity, but a satellite can have a considerable speed, because of the obvious curvature of the orbit at long range. > The following sighting on Monday, May 14, 2001 at approximately 9:30 > PDT, has prompted me to join SeeSat-L. On that night, I watched a > satellite traveling north to south through binoculars (16 x 42). At > approximately 45 degrees above the southern horizon, I saw a dim flash > and the one object very clearly and suddenly became two objects. It could have been one satellite entering the Earth's shadow, and two other satellites (at higher elevation above ground) flashing or tumbling to better visibility. 45 deg S at that time is a location where many satellites meet the shadow. > > Both objects sharply diverted from the original trajectory, one > traveling toward the southeast, the other to the southwest (both at > opposite yet equal angles to the original trajectory). I was able to see >... > My apologies for not recording any more detailed information about the > sighting. I was quite startled and was not able to clearly recall > details such as, "Were the two objects of equal brightness?" > Your data may be too vague to allow an identification. Is "approximately 9:30" 9:15-9:45 ? Or 9:29:30-9:30:30 ? Is "45 degrees above the southern horizon" 30-60 degrees, or 43-47 degrees, above 150-210 degrees azimuth, or above 175-185 azimuth ? Within 10 minutes and +- 25 degrees I find 12 easily visible satellites. The memory of direction of motion is often easier to reconstruct. Imagine that you are holding the binoculars steady, and you have a 360 degree scale around the field-of-view, with 0 upwards, 90 to the right (3 o'clock). In the attached image from Rob Matson's SkyMap, you could describe Cosmos 457 rocket as going 210 degrees, Cosmos 660 5 degrees (or less), NOSS 6 (B) 335 degrees, Feng-Yun 1-1 30 degrees. This is also more accurate than trying to imagine where on the horizon the satellite might "touch down" after many minutes. A satellite moving to the SE from that position would almost have to head straight right - 090 degrees ! ----------------------------------------------------------------- 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 : Mon May 21 2001 - 09:23:18 PDT