[avoutthere]

"chaff was released by a military C130 [sic] northwest of Evansville."

Not exactly a mystery.

[edkennedy]

Uncorroborated seemingly random claim on twitter as stated in the article.

[macintux]

Uncorroborated, and also the article notes that the duration of the cloud is unusual.

[jonknee]

So why was it 50 miles across and in the air for 10 hours? That's not from a C130.