Debris from a rocket launched by China in late April is expected to re-enter Earth’s atmosphere sometime late Saturday or early Sunday, according to experts and officials.

The debris is 10-stories tall and weighs twice as much as a school bus, which is drawing concern, as experts aren’t sure where it will land. There’s a small chance it could hit New York, Los Angeles, Madrid, Rio de Janeiro, the Nigerian capital of Abuja, or Beijing, but California-based Aerospace Corporation believes there’s a 75% chance it will land in the ocean. It adds that 60-80% of the rocket remnant will burn up — but the rest will likely hit ground or water.