A Russian rocket that broke up re-entering Earth's atmosphere over the United States had ferried a French telescope into orbit, U.S. military officials said.

Early risers in Colorado and Wyoming could see glowing trails of space debris from the rocket, launched recently from Kazakhstan, the Denver Post reported Thursday.

Rocket pieces as large as boulders broke off but disintegrated into shards before they hit the two states just before sunrise, said Navy Lt. Cmdr. Sean Kelly, spokesman for U.S. Northern Command and the North American Aerospace Defense.

"It's not a big deal at all," Kelly told the Post. "It lit up the sky over Colorado. This is a routine occurrence. This happens every day. It's just that it's not over Colorado. Most of the time these things hit the ocean."

No damage was reported. The debris wasn't thought to be hazardous.

Copyright 2007 by United Press International