Pentagon tracking out-of-control Chinese rocket that could reenter Earth’s atmosphere

Washington(CNN)The Pentagon has said it is tracking a large Chinese rocket that is out of control and set to reenter Earth's atmosphere this weekend, raising concerns about where its debris may make impact.

The Chinese Long March 5B rocket is expected to enter Earth's atmosphere "around May 8," according to a statement from Defense Department spokesperson Mike Howard, who said the US Space Command is tracking the rocket's trajectory. 

The rocket's "exact entry point into the Earth's atmosphere" can't be pinpointed until within hours of reentry, Howard said, but the 18th Space Control Squadron will provide daily updates on the rocket's location through the Space Track website. The rocket was used by the Chinese to launch part of their space station last week. While most space debris objects burn up in the atmosphere, the rocket's size — 22 tons — has prompted concern that large parts could reenter and cause damage if they hit inhabited areas.

But Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, told CNN that the situation is "not the end of days."

"I don't think people should take precautions. The risk that there will be some damage or that it would hit someone is pretty small — not negligible, it could happen — but the risk that it will hit you is incredibly tiny. And so I would not lose one second of sleep over this on a personal threat basis," he said. 

"There are much bigger things to worry about."