Are any geosynchronous satellites visible with the naked eye?

Question

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.

score 16 · Accepted Answer · answered Dec 29 '13 at 19:30

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?

score 8 · Answer 2 · edited Aug 24 '16 at 05:55

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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!

edited Aug 24 '16 at 05:55

uhoh

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answered Oct 22 '15 at 16:27

Brian Ottum

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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! – uhoh Apr 04 '16 at 03:16
@uhoh: Shouldn't GEO satellites not move as seen from earth? – Eric Duminil Apr 08 '17 at 15:35
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@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. – uhoh Apr 08 '17 at 15:52
@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? – Eric Duminil Apr 08 '17 at 15:54
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@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. – uhoh Apr 08 '17 at 16:03
@No, it took me a while to figure it out as well! That's why I like this so much - it requires some thinking. – uhoh Apr 08 '17 at 16:13
if your telescope has a camera, and you can take a very long exposure or add a bunch of frames together, then composite photographs of elapsed minutes to hours show the effect very well. if you point the telescope in a direction fixed to the earth, then in your time-lapse combined image, stars will be streaks, and dots will be geostationary satellites. if you have a tracking mount that can be set to a fixed direction with respect to the stars (constant right ascension and declination rather than constant azimuth and elevation), then stars will be dots and streaks will be satellites. – Ryan C Sep 11 '20 at 15:08

score 1 · Answer 3 · answered Apr 02 '22 at 09:33

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Voila, 4th magnitude geostationary satelite:

answered Apr 02 '22 at 09:33

Ilgonis Vilks

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Can you add some information to your answer for those that don't care to watch the video? This is almost a link-only answer. – Organic Marble Apr 02 '22 at 14:53
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While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review – Fred Apr 02 '22 at 18:02

Are any geosynchronous satellites visible with the naked eye?

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