2 Huge Pieces of Space Junk on Collision Course for Tonight Now Have 10 Percent Chance of Direct Hit

Two large pieces of space junk weighing more than 2.8 metric tons in total now have a greater than 10 percent chance of a direct collision, experts said Wednesday.

California-based company LeoLabs, which tracks space debris, is predicting that the two objects—a defunct Russian satellite and old Chinese rocket section—will make a close approach at 8:56 p.m. ET on Thursday (12:56 a.m. UTC on Friday) at an altitude of 616 miles above the South Atlantic Ocean.

"This event continues to be very high risk and will likely stay this way through the time of closest approach," LeoLabs tweeted on Wednesday.

Current tracking data from LeoLabs indicates that the two objects will miss each other by 39 feet. But this estimate comes with significant uncertainty—specifically, the figure could be off by up to 59 feet, LeoLabs said.

The objects will be travelling toward each other at a relative speed of around 32,900 miles per hour.

As the two objects move closer to each other, LeoLabs is updating its calculations regarding the probability of a collision.

On Tuesday, the company said this probability was between one and 20 percent. But as of late Wednesday the risk of a collision was estimated to be greater than 10 percent.

LeoLabs said it was planning to scan the sky after the close approach in order to ensure that the two objects had not collided and "hopefully confirm that no new debris is detected."

Any collision between these two objects could produce thousands of pieces of debris that may stay in orbit for "decades," astronomer Jonathan McDowell from the Harvard-Smithsonian Center for Astrophysics tweeted on Wednesday.

The astronomer said the mess that would be created by such a collision would be "very bad" and would likely result in a "significant" 10-20 percent increase in the amount of debris in low-Earth orbit.

Space debris can pose a significant risk to astronauts and spacecraft in orbit given that it's capable of travelling up to 18,000 miles per hour—which is about nine times faster than a rifle bullet.

McDowell has identified the two objects as a defunct Russian "Parus" navigation satellite and a Chinese ChangZheng-4c rocket stage, which launched in 1989 and 2009 respectively.

The Parus satellite, which will be heading south towards the South Pole at the time of the close approach, measures around 6.5 feet in diameter and 55 feet in length, McDowell said.

Meanwhile, the ChangZheng-4c rocket stage, which will be heading north towards the Falkland Islands at the tip of South America during the close approach, measures 9.5 feet in diameter and 24 feet in length.

space debris
Stock image: Artist's illustration of space debris. Two large pieces of space junk have around a 10 percent chance of colliding on Thursday evening. iStock
2 Huge Pieces of Space Junk on Collision Course for Tonight Now Have 10 Percent Chance of Direct Hit | Tech & Science