It wasn’t space debris that struck a United Airlines plane—it was a weather balloon

Speculation built over the weekend after one of the aircraft’s pilots described the object that impacted the aircraft as “space debris.” On Sunday the National Transportation Safety Board confirmed that it is investigating the collision, which did not cause any fatalities. However, one of the pilot’s arms appeared to be cut up by small shards of glass from the windshield.

Balloons said to not “pose a threat”

WindBorne has a fleet of global sounding balloons that fly various vertical profiles around the world, gathering atmospheric data. Each balloon is fairly small, with a mass of 2.6 pounds (1.2 kg), and provides temperature, wind, pressure, and other data about the atmosphere. Such data is useful for establishing initial conditions upon which weather models base their outputs.

Notably, the company has an FAQ on its website (which clearly was written months or years ago, before this incident) that addresses several questions, including: Why don’t WindBorne balloons pose a risk to airplanes?

“The quick answer is our constellation of Global Sounding Balloons (GSBs), which we call WindBorne Atlas, doesn’t pose a threat to airplanes or other objects in the sky. It’s not only highly improbable that a WindBorne balloon could even collide with an aircraft in the first place; but our balloons are so lightweight that they would not cause significant damage.

WindBorne also said that its balloons are compliant with all applicable airspace regulations.

“For example, we maintain active lines of communication with the FAA to ensure our operations satisfy all relevant regulatory requirements,” the company states. “We also provide government partners with direct access to our comprehensive, real-time balloon tracking system via our proprietary software, WindBorne Live.”