Enclosed is a photo taken on 2/10/05 of a dark line that merges with a airplane trail in the sky. I don't know what it is.

--Michael L.
Hattiesburg, Mississippi

Update: A number of people have written in suggesting that the black streak is the shadow of the contrail. Here is one such response:

"That dark line intersecting the contrail is the actual shadow of the contrail, made by the sun. I've seen this phenomenon a few times in my life, you have to be in the right place at the right time...."
Phil K.
Searsport, Maine