BEIJING, China — The large Chinese rocket that is out of control and set to reenter Earth’s atmosphere this weekend has brought about an alarming but not unprecedented situation.
Space debris has crashed into Earth on a number of occasions, including last year.
The good news is that debris plunging toward Earth — while unnerving — generally poses very little threat to personal safety. As Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, told CNN: “This is not the end of days.”
Still, the episode has fueled fresh questions about space debris, uncontrolled reentry and what precautions might need to be taken, if any.
Here’s what you need to know:
How often does uncontrolled space debris crash into Earth?
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 — an empty core stage from a Chinese rocket — 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.
“Norms have been established,” McDowell said. “There’s no international law or rule — nothing specific — but the practice of countries around the world has been: ‘Yeah, for the bigger rockets, let’s not leave our trash in orbit in this way.'”
The Chinese rocket set to enter Earth’s atmosphere this weekend, however, is designed in a way that “leaves these big stages in low orbit,” McDowell said.
“It’s really not best practice compared to what other space agencies do. They go to quite fair lengths to avoid doing this.”
When and where will the Chinese rocket reenter Earth’s atmosphere?
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.
McDowell explained that 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.
What’s the Biden administration saying?
White House press secretary Jen Psaki on Wednesday wouldn’t say if the US would commit to calling on China to pay compensation in the event of damage caused by the rocket.
“We’re not at this point — we’re certainly tracking its location through US Space Command, and hopefully that’s not the outcome that we are working through,” she told reporters.
“Let me first say that US Space Command is aware of and tracking the location of the Chinese Long March 5B in space, and obviously, the Space Command would have more specifics on that tracking and any additional details,” Psaki said, adding that the US “is committed to addressing the risks of growing congestion due to space debris and growing activity in space, and we want to work with the international community to promote leadership and responsible space behaviors.”
A Defense Department spokesman told CNN the US military is not considering a kinetic strike option to break up the rocket. The US has demonstrated the capability in the past to shoot down debris entering the atmosphere.
