Thanks jbow. Will be taking the little ones out tonight to see this.

Pardon my ignorance, but isn't this happening every day?

I'm thinking you are joking so I don't want to seem pedantic. But here's a basic explanation. 
 
The viewing opportunities are the result of angles of incidence and reflection.
 
You need the placement of the sun, the ISS, and yourself to all be in the right place at the right time.
 
If you lay on your back and star gaze right at, and just after, sunset you can observe dozens of satellite reflections streaking across the sky. It seems random, but I suppose you can learn which ones they are because the ones you see have to part of the incidence and reflection coincidence and that is predictable. The ones that don't reflect light down towards you simply *fall* by your particular location unnoticed.
 
I'm still curious about why the ISS is the brightest thing in the sky. Maybe it is because it is the most massive satellite that is up there?
 
best regards,
mike

Why is it so bright?
 
With the solar panels it about the size of a football field. Yes is is falling but a small rocket pushes it back up about every two weeks. It comes over about every 90 minutes or so.
 
https://itunes.apple.com/us/app/iss-spotter/id523486350?mt=8
 
https://play.google.com/store/apps/details?id=com.runar.issdetector&hl=en
 
https://twitter.com/ISS_spotter
 
another cool site: http://www.heavens-above.com/ check out the irridium flares. They are satellites that flash in the daytime wheh the sun catches the solar panels. If you know where and when to look you can see them too.
 
J

Wow!
 
Thanks.

Spaceweather.com has a simple satellite tracker for your location. ISS is easy to spot :-)

Of course none of the satellites or the ISS pass on the same exact orbit each time. The ISS is easy to see when the conditions are all correct.  The Iridium satellites are more "fleeting" in what they do..... hence they are called flares.... again their solar arrays are reflecting the sunlight to the earth but the "spot" they cast on the earth is smaller....closer in size to 30 mile diameter..... and traveling at 18,000 mph so if you are in it, it's very bright but it lasts only a few seconds as the spot of light passes your location.
 
You can many times see the satellite coming as a very faint spot of moving light..... then as the cone of light hits your location it flares up and down literally in 3 to 8 seconds and it's gone.  The closer you are to the center of the cone on the ground the brighter it is..... These are mostly visible anywhere from soon after sunset to around 11 pm and then again in the 3 to 4 hrs before sunrise.... the angles are best closer to the sunset/rise for a nice bright viewing....
 
The ISS generally keeps the same brightness throughout it's pass..... which can last from a minute or less to several minutes....
 
Then of course, there are all the other satellites which are also visible.  I often see them when camping. Laying on a lounge chair under the open, dark sky as the fire is dying and the sky is clear..... they are visible as dim, but fast moving, non-blinking lights on a straight path in the start field. Jets and other aircraft have blinking lights on them that is easily visible to ground observers. The satellites are the non-blinking objects..... and there are over 3000 of them up there so seeing one is just a matter of being patient on any given clear dark night.

I just looked but couldn't see it.  Of course, right now I can't see much of anything after accidentally looking into the eye of the sun...
 
(But Mama, that's where the fun is!)

Do you have sun spots Craig?  Oh and.. was the fun there?
 

jbow
Why is it so bright?
 
With the solar panels it about the size of a football field. Yes is is falling but a small rocket pushes it back up about every two weeks. It comes over about every 90 minutes or so.
 

This is close, but not quite correct.
ALL satelites in orbit are falling.  That doesn't mean they're getting closer to the ground though because they are also traveling horizontally at such a speed that the curved surface of the Earth falls away at the same rate, hence they appear to be "flying".  ISS doesn't have rockets to keep it in orbit,  just a few small thrusters to make small corrections to its orbit.
 
Yes,  most satelites in LEO (Low Earth Orbit) take about 90 minutes (depending on their exact height) to circle the Earth, but most satelites (including ISS) have an orbit which is angled in relation to Earths axis so they can over-fly (over-fall) most of the surface.
However, the Earth continues to turn during that time so a ground observer watching a pass of ISS would be in the wrong place 90 mins later for the next pass.  The Sun and ISS have to be in the right place for the light to reflect to earth and be seen, soon after sunset and just befor dawn, and this must coincide with ISS being in the right part of its orbit to be within your field of view.  It can often be several weeks between viewing opportunities, assuming there is no cloud cover on the specific day to choose to look...
 
 
The best view I had of ISS was 3 or 4 years ago when it passed almost directly over Englands south coast (about as far north as ISS goes) on a perfectly clear evening (where I was) with a space shuttle just a few miles away chasing it down for docking.