I am an early riser..so I often have to let the dog out while the coffee is brewing..this am I looked out to the eastern sky and Im sure I saw the ISS. I checked the science.nasa website which directed me to the link below. You can check location of your area as to when you may sight it..sure enough, it is timed to be over my sky's this month. THe last time I saw it was in Nova Scotia 3 yrs ago..what a sight!!!!!
Although I did not check the ephemeris for your location vs the ISS it is highly likely you saw it. Ephemeris are nothing more than the numbers that Kepler defined 400 years ago which describe orbital motion. Those same numbers are still used today albeit in much more sophisticated orbital models (for the curious look up SGP4 for low earth orbits and SGP6 for deep space calculations). Ephemeris are also commonly called "one line Charlie elements" or "two line element sets." There are also three line sets used for extremely precise orbit predictions but you wll not find a lot of references to those so you can safely ignore that reference. Again for the curious, if you want to know more about three liners look up things like the "Grace" mission run out of the Center for Space Research at U.T. Austin.
For some REALLY REALLY good tutorials go to Dr. T. S. Kelso's site - www.celestrak.com. If you are a glutton for math punishment order the book "Fundamentals of Astrodynamics", US Air Force Academy
OK this next sounds more complicated than it is - think of those curved mirrors they use in hospitals to look around corners. The ephemeris themselves only give you satellite location, usually relative to earth center or in specialized cases relative to the sun center (Lagrange point orbits such as the James Webb Space Telescope). What gives you the ability to see the spacecraft is if their is a coincidence of the satellite zentith angle relative to you and the solar zentih angle relative to both the satellite and you; that is the satellite has to be above your horizon, the sun must be below your horizon but above the satellites horizon. Again, for the curiuous, the coordinate system for earth center is, one axis through the earth's poles, one axis through the equator at longitude zero and one axis through the equator at 90 degrees east of that.
There is plenty of good information on line - just google satellite orbit calculations. Here is a link to a very simplistic but accurate and easy to use orbit calculator:
It is a Java applet so you need to have Java enabled in your browser. Far more sophisticated calculators are available on line but this one is a nice intro - and HEY it's free - smiles.
No thanks, I am not into Mathmatical punishment and or any other..
It looks like we had the same links up..I was on science.nasa as well.
THe interesting thing is the shape of the light that beams from it..It not like head lights that spread into the dark..with lighter going to darker, so to speak. Im not sure if I can explain it.. It was dawn and it stood out very clearly, in the background to the east, the suns early morning light was actualy weaker...Only if my camera was ready for that one..So its heading west for other North Carolinians who may be interested:)
You guys have to stop posting links like that! I spent half the afternoon checking it all out! It's too fascinating to just let it go! Now I'm behind schedule...but that's ok....it was worth it to me!
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RumRunner
Although I did not check the ephemeris for your location vs the ISS it is highly likely you saw it. Ephemeris are nothing more than the numbers that Kepler defined 400 years ago which describe orbital motion. Those same numbers are still used today albeit in much more sophisticated orbital models (for the curious look up SGP4 for low earth orbits and SGP6 for deep space calculations). Ephemeris are also commonly called "one line Charlie elements" or "two line element sets." There are also three line sets used for extremely precise orbit predictions but you wll not find a lot of references to those so you can safely ignore that reference. Again for the curious, if you want to know more about three liners look up things like the "Grace" mission run out of the Center for Space Research at U.T. Austin.
For some REALLY REALLY good tutorials go to Dr. T. S. Kelso's site - www.celestrak.com. If you are a glutton for math punishment order the book "Fundamentals of Astrodynamics", US Air Force Academy
OK this next sounds more complicated than it is - think of those curved mirrors they use in hospitals to look around corners. The ephemeris themselves only give you satellite location, usually relative to earth center or in specialized cases relative to the sun center (Lagrange point orbits such as the James Webb Space Telescope). What gives you the ability to see the spacecraft is if their is a coincidence of the satellite zentith angle relative to you and the solar zentih angle relative to both the satellite and you; that is the satellite has to be above your horizon, the sun must be below your horizon but above the satellites horizon. Again, for the curiuous, the coordinate system for earth center is, one axis through the earth's poles, one axis through the equator at longitude zero and one axis through the equator at 90 degrees east of that.
There is plenty of good information on line - just google satellite orbit calculations. Here is a link to a very simplistic but accurate and easy to use orbit calculator:
http://science.nasa.gov/Realtime/jtrack/3d/JTrack3D.html
It is a Java applet so you need to have Java enabled in your browser. Far more sophisticated calculators are available on line but this one is a nice intro - and HEY it's free - smiles.
Best,
Runner
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likeaneagle
RR-
THanks for your imput..
No thanks, I am not into Mathmatical punishment and or any other..
It looks like we had the same links up..I was on science.nasa as well.
THe interesting thing is the shape of the light that beams from it..It not like head lights that spread into the dark..with lighter going to darker, so to speak. Im not sure if I can explain it.. It was dawn and it stood out very clearly, in the background to the east, the suns early morning light was actualy weaker...Only if my camera was ready for that one..So its heading west for other North Carolinians who may be interested:)
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I Love Bagpipes
Cool!!
8:26 tonight for 3 minutes.
I last saw it, uhhhh, 5 years ago?
LOL..."mathematical punishment"....hee
Likeaneagle/Rumrunner do you know what directions we should look from our NC locations? (without the mathematical punishment..)
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krys
You guys have to stop posting links like that! I spent half the afternoon checking it all out! It's too fascinating to just let it go! Now I'm behind schedule...but that's ok....it was worth it to me!
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likeaneagle
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likeaneagle
THanks RR, I knew you had a Science side..:)
Krys, Isnt it fun to explore outside our boxes..
IBL- try to get away from tree's to get a good look..Its a little hillier out there.
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