The rocket part should reenter the Earth’s atmosphere between 1 p.m. and 5 p.m. ET Wednesday, according to CNN. It is moving at an estimated 4.7 miles per second, and its reentry latitude will likely be anywhere between 63 degrees north to 63 degrees south of the equator.
While the international norm for spent rocket parts or spacecraft is to make a controlled reentry and drop to Earth above an uninhabited area, such as a stretch of the Pacific Ocean, Russia did not follow best practices. In this case, it was accidental, experts say.
Out-of-Control Part Belongs to the Angara-A5 Rocket
Russia launched the Angara-A5 heavy-lift rocket from the Plesetsk spaceport in the northwest region of Russia on Monday, Dec. 27. It was a test run for the upper rocket part known as the Persei booster.
The Persei booster was about 33 feet long, according to Jonathan McDowell, an astronomer at the Center for Astrophysics – Harvard & Smithsonian. But it was carrying roughly 16 tons of propellant.
McDowell told CNN that the rocket part’s total mass is mostly liquid and will probably burn up in the Earth’s atmosphere, “I think.” He added that the part’s tumble toward Earth was likely an accident.
“It was meant to end up in an orbit where it would stay for many thousands of years. The rocket failed to restart,” McDowell said.
The launch was reportedly conducted by the Russian Ministry of Defense, not Roscosmos, Russia’s space agency.
100 to 200 Tons of Space Debris Enter Earth’s Atmosphere Every Year
Meanwhile, scientists across the rest of the world have been trying to guess where the rocket part will hit Earth.
“It’s safe to say that in the next 24 hours it will be down but where, nobody can say, because in the window of several hours it will do several revolutions around the globe,” Holger Krag, the head of the European Space Agency’s Space Debris Office, told CNN.
According to Krag, roughly 100 to 200 tons of space debris reenters the Earth’s atmosphere in an uncontrolled manner on an annual basis. Most of it burns up upon coming into contact with the Earth’s atmosphere. But there is a chance that large pieces, like the rocket part, could cause damage if they hit inhabited areas.
Space debris has hit one human in recorded history: a Texas woman named Lottie Williams in 1997. She survived the encounter.