An Infrared Astronomical Satellite (IRAS) and the Gravity Gradient Stabilization Experiment (GGSE-4) are two defunct satellites that almost collided with each other on Wednesday. Instead of coming within a few feet of each other and possibly colliding, they sped past each other in opposite orbits. The possible collision could have caused thousands of pieces of debris to be sent through space at remarkable speeds. According to Agence France-Presse, at 6:39 PM on Wednesday, the crossover occurred about 560 miles above Pittsburgh. Experts said, “any debris created would not have been a threat,” adding that 20,000 pieces of softball-sized debris currently orbit Earth.
Launched in 1983, the IRAS was part of a joint mission with NASA, the Netherlands and Britain. GGSE-4 was launched in 1967 by the U.S. Air Force as part of an experiment.