Welcome to the list, David! Based upon your description and simulated image, the object traversed about 0.3 deg in 15 to 20 s, equivalent to an angular velocity of 0.02 deg/s. It depends upon the type of orbit, but in round numbers, an orbiting object would have to be at a range of about 10,000 km to move that slowly. I know of only one class of very large satellite in a high orbit; it is an electronic intelligence gathering satellite, thought to have an antenna about 100 m in diameter. The U.S.A. launched three such satellites into Molniya orbits between 1994 and 1997. You would have to observe one of those orbits at a range of about 15,000 km to yield an angular velocity of 0.02 deg/s. At that range, a 100 m object would subtend 1.4 arc sec, far smaller than the 10 to 15 arc sec that you reported, and pushing the limit of resolution of a 4 inch telescope, let alone seeing any detail. So, I know of no orbiting object that could explain what you observed. In a subsequent post, you asked whether or not a LEO object moving toward you at low elevation could move that slowly. On an overhead pass, ISS (400 km orbit) moves at 0.07 deg/s when it is at the horizon. A Lacrosse satellite (650 km orbit), would move at 0.06 deg/s in the same circumstances. So, the answer is no. Thank you for sharing your observation, and please do not hesitate to share any future possible satellite sightings. Ted Molczan ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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