Wonderig....

How far up into the sky can be actually seen through a pair of hi-power binoculars or scope?I'm talkiing in miles,seen some people being able to see satellites at night.Is it possible to maybe catch a clear glimpse of aircraft that can fly in low-orbit?Just curious.

With good light conditions, yes, it is possible to see low orbit satelites such as the ISS.

I can often see satelites with the naked eye. (no details of course) by the way and speed they move.
There are a few websites that give you more info on when and how you can see the ISS.
Sorry...I'm lazy this moring, you have to google for it yourself

If you live in a city its very hard to see low orbit satelites, damn street lights

Every star you see is billions of miles away so you can see billions of miles.

I saw three satellites crossing overhead last night within the space of about 5mins, with my naked eye.

There is a brilliant site (sorry can't remember where now) that lists all 'known' satellites and their trajectories.

[Edited on 13-8-2003 by johnb]

If you are a non smoker you will stand a better chance of seeing dimly lit, or deep space objects. Smoking ruins your night vision. Away from the city here in Arizona many star clusters and galaxies are visible with the naked eye.