In article <a%kOd.93$1S4.4658@news.xtra.co.nz>, "Geoff Blackmore" 
<geoff_184@(removethispart)xtra.co.nz> says...

NASA's UFO imagery:

Why resort immediately to an unlikely explanation when there are a 
number of vastly more likely ones?

http://antwrp.gsfc.nasa.gov/apod/ap050208.html

My guess: an earthly satellite. There are loads up there which are not 
usually visible and so not interesting to heavens-above, but now and 
again one will happen to turn some shiny part of its anatomy to the sun 
and 'flare', i.e. we see a transient specular reflection of the sun. 
These are often very bright, and it's extremely difficult, if even 
possible at all, to work out from which satellite they come.