It is very easy to spot LEO satellites during dusk or dawn. I am wondering if satellites further out in a geosynchronous orbit are also visible. Of course, if even possible, these would appear more stationary than any LEO satellites.


No, and the reason is simple enough. GEO is at an altitude of 35,786 kilometres (22,236 mi) above the Earth's equator and no satellites in geostationary or geosynchronous (GSO) orbit are large enough to reflect sufficient amounts of light towards the observer with their truss and solar panels to be visible to the naked eye on the surface of the Earth. They're simply too far away and the atmospheric diffraction doesn't help either, further blurring small and faint objects of high apparent magnitude.

If you're extremely lucky with weather and other conditions from where you're observing (especially the light pollution, described e.g. by Bortle scale, should be as low as possible to detect such faint objects), you might be able to see some with powerful binoculars or a hobbyist-grade telescope, as claimed on e.g. this website. I'd imagine though that it would only be possible from high altitudes where you'd deal with a lot smaller atmospheric effects and shouldn't be much light pollution. Observing them when transiting a brighter object in the background shouldn't help much either, again due to diffraction. If you're incredibly lucky though (just musing with infinitesimally remote chances here), a foreground object in lower orbit or upper atmosphere would momentarily align with a GEO satellite, and you might, might be able to observe slight lensing effect on its body, if the foreground object had magnifying optical properties, say a burst of translucent propellants ejected out of a rocket's nozzle. But what are the chances of that happening?


No, but they are easily seen with a small telescope on a sturdy mount. March and September are the best times. Use an app to help you. My favorite way is to keep M11, the Wild Duck Cluster, in view with a medium power eyepiece. Every few minutes, a "star" will slowly track through the southern edge!

  • $\begingroup$ Wow, I like that! At 40 degrees North latitude, the geostationary "ring" is a big (but not great) circle at about 6.25 degrees South declination. If your drive has a computer, you could set it to point at a GEO satellite, shut off the motor, and wait for the Wild Duck Cluster to "fly through" instead! $\endgroup$ – uhoh Apr 4 '16 at 3:16
  • $\begingroup$ @uhoh: Shouldn't GEO satellites not move as seen from earth? $\endgroup$ – Eric Duminil Apr 8 '17 at 15:35
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    $\begingroup$ @EricDuminil this is a trick to find them. From mid-northern latitudes on the surface of the Earth, a line in the direction of the easy-to-spot M11 passes through Earth's equatorial plane at the geostationary distance. This line sweeps through the satellites. So if you keep it pointed at M11, you'll sweep past one satellite after another. Could be done with a manual or automatic mount. $\endgroup$ – uhoh Apr 8 '17 at 15:52
  • $\begingroup$ @uhoh: That's good to know. But I mean : shouldn't GEO satellites always have the exact same position in the sky? Like stars and not LEO satellites? $\endgroup$ – Eric Duminil Apr 8 '17 at 15:54
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    $\begingroup$ @EricDuminil yes, but the stars do not. Stars move in the sky. So if you track or follow M11, you will pass through the fixed positions of one GEO satellite after another in the sky. This trick only works at mid-northern latitudes. $\endgroup$ – uhoh Apr 8 '17 at 16:03

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