Flyover by International Space Station

On July 14, 2001 I watched the International Space Station (ISS) fly over my home near Flint Michigan. I was amazed at how bright and how BIG it looked.  Well, not as big as the moon or anything, but it looked like a really huge star.  It moved at a pretty stately pace too.  It took about 3 minutes to cross the sky.  

If you want to try watching for it yourself, here's some links to NASA sites that tell you about it:

• NASA Manned Spaceflite page
• NASA's Sightings page - tells you what you can see, and when
• NASA's directions for interpreting sightings data
• Information from NASA about the International Space Station

Double-click the picture to see bigger version

Click here to watch video (650 KBy)

The ISS is pretty big, which make it easy to see. Most sightings are at dawn or dusk, because that's when the sun and earth are positioned to best illuminate the ISS (remember you only see it by reflected light).  This photo was taken at 5:27 am in my front yard in Flushing MI.  The ISS moved from SW to ESE, at about 56 degrees of elevation.

Think About This...
Why is it that you only see the station at dawn or dusk??  The station has no light of its own.  You see it when it reflects sunlight back to you.  You can't see it in the middle of the night because the earth is between the sun and the station, and casts it into shadow.  But you can see it at dusk or dawn because the sun, earth, and station are positioned in such a way that the sun hits the station, and you can see the illuminated side.  

If you get a chance, try watching some morning sightings, AND some evening sightings.  Do you notice a difference in the way the ISS looks?  In the morning, it starts out really bright (when its in the western sky), and gets dimmer once it passes overhead.  During evening sightings, it starts out kind of dim, then gets brighter once it passes overhead.  Can you figure out why??