Someone call Mulder and Scully. At approximately 9 p.m. local time on Thursday night, the sky lit up across the Pacific Northwest in what looked like a wildly intense, super-concentrated meteor shower — or maybe even an alien attack. Videos surfaced on social media almost immediately, with witnesses across the region speculating that it could be a comet breaking up or, more darkly, a plane crashing.
In fact, it was the second stage of a SpaceX Falcon 9 rocket burning up as it reentered the atmosphere, according to Center for Astrophysics astronomer Jonathan McDowell, whose tweet explaining the incident went viral.
The rocket launched on March 4, successfully delivering its payload of 60 SpaceX Starlink satellites to orbit. While the massive first stage of a Falcon 9, or the booster, is designed to land back on Earth so it can be refurbished and reused, the smaller, three-ton second stage is designed to disintegrate as it falls back through the atmosphere.
Under normal circumstances — or nominal ones, in rocket-speak — a Falcon 9 second stage returns to Earth in a controlled manner shortly after delivering its payload, using a deorbit burn of its Merlin engine to reenter over the Pacific Ocean. If any rocket parts survive the intense firestorm of reentry, there's very little chance of those pieces causing any damage on the ground (or, in this case, the sea).
But there was a malfunction with this particular second stage that resulted in a slow, uncontrolled deorbit over about three weeks, with the grand finale happening on Thursday.
While astronomers like McDowell had been monitoring the second stage since the launch, it was nearly impossible to predict precisely where it would reenter — the rocket was, after all, zipping around the Earth at 17,000 miles per hour. Notoriously tight-lipped, SpaceX has not provided any comment about the rogue second stage.
Though the fiery display might've been alarming — and certainly mesmerizing — the event fortunately posed very little threat to people on the ground. The rocket likely broke up at an altitude of 40 miles, more than five times as high as commercial airliners, and it's unlikely that anything larger than a few scraps of metal made it back to Earth.
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