I don’t usually post two identical stories within a few days of one another, but when I saw this image on SpaceWeather.com I had to comment on it. On Friday, I was captivated by the astounding astrophotography by Nicolas Biver as he tracked the space station with video camera and telescope, to capture some great detail of the manned outpost as it passed over France. With a bit of luck and a whole world of skill, Biver observed a bright space station flare.
Next up, it’s the turn of Martin Gembec. On May 2nd, he grabbed this superb trail as the station passed through the distinctive edge-on disk of our galaxy over the Czech Republic. What’s more, the station flared as its huge solar arrays reflected sunlight through Gembec’s ‘scope… right at the moment when the station travelled through the hazy starlit disk of the Milky Way.
“We were watching a bright flyby of the space station when the ISS surprised us with a big flare in the Milky Way,” said Gembec. “At maximum, the ISS reached magnitude -8.”
A magnitude of -8 makes this flare a beast; that’s 25× brighter than Venus and 400× brighter than the star Sirius.
In the photo above, there is a rather ominous piece of kit attached to a boom reaching into the centre of the image. This is a reflection of Gembec’s Canon 30D camera (that took the picture as the ISS passed overhead) in an all-sky mirror. The mirror is in a concave shape to collect the starlight from the sky, bouncing the light into the camera lens. It acts much like a satellite dish; except it doesn’t bounce and focus radio waves into an antenna, the all-sky mirror reflects visible light and focuses it into the open camera shutter. As you can see, the results are visually stunning.
Source: Space Weather
astroengine.com 
All sky mirror? I’ve seen a bunch of camera setups before, but never this one. Pretty clever!
I don't know; have you heard of Google Sky??
This seems like the most comprehensive blog on this nicheRegards