Can you see lights on satellites from the ground?

• Can you see lights on satellites from the ground? by mgfitter on 01 Dec, 2014 01:42
• Does anyone know if it is possible to see man-made lights aboard spacecraft as they pass overhead in full darkness, as opposed to reflected sunlight?
  
  For example, are the navigation strobe lights on Dragon visible from the ground?
  
  -MG.
• #1 by rdale on 01 Dec, 2014 02:02
• No. I suppose maybe if you are looking in a high powered telescope, but remember the distances involved here. If someone pops up a AA flashlight just 5 miles away from you on a mountain top, you aren't going to see it
• #2 by kevin-rf on 01 Dec, 2014 12:09
• There was a Japanese cubesat, FITSAT-1 a couple of years back that blinked morse code messages to ground. Don't remember the results. Did anyone spot it with the unaided eye?
  
  Official website: http://www.fit.ac.jp/~tanaka/fitsat.shtml
• #3 by pericynthion on 01 Dec, 2014 17:02
• AIUI the FITSAT LEDs were observed through binoculars and telescopes but not the unaided eye.
• #4 by mgfitter on 02 Dec, 2014 01:02
• I wonder what it would take to make some light bright enough to be seen from the ground with the unaided eye? And how much energy would that require?
  
  -MG.
• #5 by pericynthion on 02 Dec, 2014 01:11
• I'm pretty sure the OPALS laser com experiment would be visible if it were in the visible spectrum rather than IR.  Of course, the spot size is only about 1 km wide so you'd have to be standing in the right place.