Two Satellites Are About to Come Extremely Close to Crashing Above Pittsburgh Tonight

Two decommissioned satellites will narrowly avoid colliding with each other, experts have warned.

LeoLabs—a company that provides space debris tracking and collision prevention services for Low Earth Orbit—said the close approach will take place on January 29 at 11:39 p.m. UTC (6:39 p.m. EST) when the spacecraft will be around 560 miles directly above Pittsburgh, Pennsylvania.

According to LeoLabs, the two objects will likely miss each other by only around 50-100 feet while traveling at a relative speed of around 33,000 miles per hour.

Given the size and predicted trajectories of both objects, LeoLabs has computed the probability of a collision at around 1 in 100. While this is clearly unlikely, the California-based company's CEO Dan Ceperley said that accurately predicting the paths of fast-moving satellites in space is challenging.

If the two objects did collide, the impact could create huge problems in low Earth orbit for other spacecraft.

"There would be thousands of pieces of new debris that would stay in orbit for decades," Ceperley told LiveScience. "Those new clouds of debris would threaten any satellites operating near the collision altitude and any spacecraft transiting through on its way to other destinations. The new debris [would] spread out and form a debris belt around the Earth."

The two defunct satellites in question are known as the Infrared Astronomical Satellite (IRAS) and the Gravity Gradient Stabilization Experiment (GGSE-4).

According to NASA's Jet Propulsion Laboratory, the IRAS—launched in 1983—was the first space telescope to survey the sky in infrared. It measures 11.8 by 10.6 by 6.7 feet and weighs around 2,400 pounds, WPXI reported.

During its 10-month mission, IRAS—a joint project between NASA, the Netherlands' Agency for Aerospace Programmes and the U.K.'s Science and Engineering Research Council—made several discoveries. These included six new comets and the core of Milky Way.

On the other hand, GGSE-4—launched in 1967—was developed by the U.S. Air Force as part of an experiment aimed at investigating spacecraft design. It is much smaller than IRAS, measuring only around 10 pounds, WPXI reported.

Infrared Astronomical Satellite
Artist's illustration of the Infrared Astronomical Satellite. NASA/JPL-Caltech

If the two objects do collide, there is no danger to people on the ground as any debris entering the atmosphere would burn up before reaching the surface, space archaeologist Alice Gorman from Flinders University told ScienceAlert.

"Events like this highlight the need for responsible, timely de-orbiting of satellites for space sustainability moving forward. We will continue to monitor this event through the coming days and provide updates as available," LeoLabs said in a statement on Twitter.

Two Satellites Are About to Come Extremely Close to Crashing Above Pittsburgh Tonight | Tech & Science