Heads up: Rocket part from China to fall on Earth

A section of a large Chinese rocket is falling back to Earth and is expected to crash sometime Saturday. It could strike an inhabited area, experts warn.

Where it will hit “cannot be pinpointed until within hours of its reentry,” the Pentagon said in a statement this week. U.S. officials are watching the rocket’s trajectory. Secretary of Defense Lloyd Austin is “aware and he knows the space command is tracking, literally tracking this rocket debris,” Pentagon spokesman John Kirby said.

Here’s what you should know:

Did China launch a rocket?

Yes. The Long March 5B rocket carrying China’s Tianhe space station core module lifted off from the Wenchang Space Launch Center in southern China’s Hainan province April 29. Known as the Heavenly Harmony, the space station will be China’s first to host astronauts long-term. China plans 10 more launches to carry additional parts of the space station into orbit.

Is the Chinese rocket falling to Earth?

Yes, and “it’s potentially not good,” Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, told the Guardian. Usually discarded core rockets, or first-stage rockets, plunge to the sea soon after liftoff and don’t go into orbit like this one did.

China’s space agency has yet to say whether the core stage of the huge rocket is being controlled. No one knows for sure. McDowell told CNN that pinpointing where debris could be headed is almost impossible because of the speed the rocket is traveling – even slight changes in circumstance drastically change the trajectory. The debris will be dragged toward Earth by increasing collisions with molecules in the Earth’s atmosphere, Space News said. Aerospace Corp. expects the debris to hit the Pacific near the equator after passing over eastern U.S. cities.