posted on Aug, 7 2009 @ 11:55 AM
Originally posted by s.one.z
the lights me and my girlfriend saw where passing the nightsky very fast, in different directions and with high speed at, what i can tell, a high
altitute (compared to airplanes)
Satellites orbit the Earth at various heights, the 'lowest' being two to five hundred miles up. The ISS for example is about 220miles high on
average (it varies a little). The Hubble Space Telescope is about 350 miles up. These are classed as low orbits. There are around 8,000 satellites out
there at this height and maybe 100,000 bits of debris. All travelling around 17-20 thousand MPH. There are another cloud orbitting at about 20,000
miles out. These are geostationary and have the same angular velocity as the Earth, so they appear to remain stationary in space.
how come does a satellite (if they really were) is shining as bright as a star? is it sun reflection, spotlights (?!) or reflecting solar
It's all due to reflected sunlight. At these heights, the sun is still shining when on Earth it's dark. Of course there are times of night when you
can't see any satellites because the sky is in total Earth shadow. A few hours around local midnight when it is impossible to see satellites. Any
bright light moving across the sky at midnight can't be a satellite.
the ones we have seen passed the night sky in about 20-30 seconds
Satellites can't cross the entire sky (from horizon to horizon) in much less than 6 minutes. It's simple orbital mechanics. The ISS takes 6 minutes
when it crosses in a high pass (the visual elevation varies every pass due to the Earth and the satellite both turning). Very high satellites (500
miles or so) take much longer, even though their speed is higher than the lower orbits.
they moved in different directions at different speeds (maybe different altitudes aswell?
They move in almost every direction.
how do the satellite operation companys manage not to crash their satellites with others?
Space. It's a big place. Crashes are very rare, but do happen. There was one a few months ago. It created another cloud of debris, maybe 10-20,000
pieces. All the stuff larger than a baseball is tracked by NORAD so they know where everything is at any time.