A large Chinese rocket that is out of control and set to re-enter Earth’s atmosphere this weekend has brought about an alarming but not unprecedented situation.
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.
Pinpointing where debris could be headed is almost impossible at this point because of the speed the rocket is traveling, with even slight changes in circumstance drastically changing the trajectory.
“We expect it to reenter sometime between the eighth and 10th of May. And in that two-day period, it goes around the world 30 times. The thing is traveling at like 18,000 miles an hour. And so if you’re an hour out at guessing when it comes down, you’re 18,000 miles out in saying where.”
Still, the ocean remains the safest bet for where the debris will land, he said, just because it takes up most of the Earth’s surface.
Space debris has crashed into Earth on a number of occasions, including last year.
The good news is that debris plunging toward Earth generally poses very little threat to personal safety.
Most pieces will burn up in the Earth’s atmosphere before having a chance to make an impact on the surface. But parts of larger objects, like rockets, can survive reentry and potentially reach populated areas.
Last year, one of the largest pieces of uncontrolled space debris ever passed directly over Los Angeles and Central Park in New York City before landing in the Atlantic Ocean.
Weighing in at nearly 20 tons, the debris is an empty core stage from a Chinese rocket. It was the largest piece of space junk to fall uncontrolled back to Earth since 1991 and the fourth biggest ever.
The only larger pieces were from NASA’s Skylab space station in 1979, Skylab’s rocket stage in 1975 and the Soviet Union’s Salyut 7 space station in 1991. The space shuttle Columbia from 2003 could be added to that list since NASA lost control of it on its descent back to Earth.
This doesn’t happen more often because space agencies around the world have generally tried to avoid leaving big objects in orbit that have the potential to reenter Earth’s atmosphere and that they cannot control.