Chris L Peterson wrote:

On Mon, 30 Apr 2007 20:03:37 +0000 (UTC), Andrew Smallshaw
wrote:

I've lost images due to contrails, mostly because a passing contrail
resulted in loss of the guide star.

Me too Chris.

Several times each year I see
conditions that cause long lasting contrails to develop into a kind of
high, thin overcast that really damages transparency. I'm not located in
a high traffic area.

There is an interesting article on this particular issue in the latest
issue of Astronomy Now (Britain). It apparently impacts both the Hubble
and ISS as well.

Anthony.