re: Spitzer spots a comet inside our solar system with a dust cloud large dust cloud.
"A dust cloud 20 times larger than JUPITER!? They expect us to believe
a simple comet (which averages 10km in width) is going to drag with it a
dustcloud that is over 500,000,000 km in size?"
Jupiter isn't that big. This page gives its diameter as 142,984 km:
Jupiter
http://seds.lpl.arizona.edu/nineplanets/nineplanets/jupiter.html
So a cloud 20 times as big would be about 2.86 million km across.
Bob Clark