Hi Rob and list, >Large solar observatories, like the one at Big Bear Lake, CA, regularly >observe solar transit events. They probably even have recordings >of some of them. Most transits are by birds, mylar balloons or >airplanes, but some are satellites. However, since it's not their >area of interest, they're not likely to go out of their way to >publish or even document such events. Sure. There are probably more than two dozen observatories around the globe which monitor the Sun constantly. Transits of birds, balloons, satellites or other objects are of no scientific interest whatsoever. >When you say solar transits are much more likely to be observed >than lunar transits, but then go on to say there have only been >two "verifiable" solar transit observations, you imply that >there must be no "verifiable" record of a lunar transit. I >guess I would ask, "verifiable" by what standard? Few people >regularly record video or still photography of such events. But >if you have multiple, experienced witnesses to the same event, >I'd say that's sufficient. I am sure such observations have been made but they haven't been reported in a forum like SEESAT-L. A scientist who makes a discovery but doesn't publish it isn't credited for it. As regards "verifiable" I would say any witnesses and testimonies that would stand up in court qualify as verifiable. The best proof is a photo or a video if it comes from a trustworthy person. Who is trustworthy? Everybody who does not falsify evidence intentionally (very easy nowadays) or who unwittingly is fooling himself and others. The latter are the more dangerous. I remember a report in SEESAT-L by someone who saw Mir against the Moon from Hawaii when Mir wasn't even above the horizon. Somebody else reported in SEESAT-L that he saw Mir sailing slowly across the lunar disc with antennas, booms and solar panels clearly discernible. In both cases people were honestly convinced they had seen what they reported. >By that standard, sunlit satellite lunar transits have certainly >been observed more than twice. A group in California observed >a Mir transit of the moon several years back which I have reported >here more than once. I consider that observation solid, and I >believe they were the first. They may even have recorded video. I am not questioning sunlit satellite transits which are fairly easy. I have seen one of Mir myself. But am not aware of an observation of a *dark* satellite transit. Actually, there may have been one by a SEESATTER a couple of years ago, but the object could not be identified (using Mike McCants' ALLDAT.TLE). >Optically, that shouldn't be any tougher than observing a silouette >solar transit. From an equipment standpoint it's actually easier, >since you don't need a solar filter. With a mobile telescope, GPS >and the desire, I doubt one would need to drive more than 100 miles >to observe such an event any month around full moon that clear >skies permit. Fully agreed. I have written a program which shows graphically where on Earth ISS casts a lunar or solar "shadow". With rare exceptions, there is always such a shadow, but it may be in the Antarctic or in the middle of an ocean. But often enough it falls on land. Usually, there are several consecutive passes separated by a day or a couple of days. 100 miles, or in my case 100 km, are often sufficient to be right on the centerline. The big and uncontrollable unknown is the weather. This has spoiled more than one transit observation (there is at least one SEESATTER (AA) who will confirm). Bruno ----------------------------------------------------------------- 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 : Sat Aug 18 2001 - 14:30:47 PDT