Fellow SeeSater's, I'm sure someone on this list can explain an observation that's quite counterintuitive. We have passes for USA193 tonight and tomorrow night. The lower (46 degrees) more distant (392 km) pass is brighter (mag = 1.8) than the higher (58 degrees) closer (334 km) pass (mag = 2.2). Why would something farther away be brighter? Assuming that the craft remains in the same attitude, it happens that you're looking at the opposite side of the object between these two passes, which could be less or more reflective, but I'm pretty sure that Heavens Above does not keep track of such factors. The sun is lower for the closer pass, but not that much (-9.4 versus -8.8 degrees). Could that be the reason for the difference? Seems like such a small difference in sun angle. Then again, in the case of the brighter pass, the observer is "in between" the sun and the object (so to speak) and in the case of the dimmer pass, the object is in between the observer and the sun. Is that it? Best Regards to all, Art Observing from our "Winter Location" in beautiful downtown Lewisburg +37.798 -80.443 Approx. 2300' above MSL Almost Heaven Group Phone 304-645-2310 http://www.almostheaven.net/ Offering direct sales of Saunas, Steamrooms. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.17.13/1213 - Release Date: 1/7/2008 9:14 AM ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Mon Jan 07 2008 - 18:52:57 UTC