Stargazers in Oregon and Washington were treated to an unexpected show last night: what appeared to be a meteor shower lazily sweeping across the night sky and most likely the remains of a SpaceX Falcon 9 rocket, which burned up as it traversed the atmosphere.
While SpaceX has not yet claimed responsibility for the spectacle, numerous meteorologists and astronomers have identified the lights in the sky as harmless missile debris. (You can see many videos of the event in the replies to this Twitter thread
“We got a really good show tonight thanks to SpaceX,” James Davenport, an astronomer from the University of Washington, told NBC. KING5“This was the top, what we call the second stage, of a Falcon 9 missile. It was launched about three weeks ago, and it did exactly what it was supposed to do: put satellites into orbit. “
“The only flaw it had was that it didn’t complete its out-of-orbit combustion, so it didn’t come down when and where we expected it. It has been waiting to fall for the past three weeks and we got lucky and it came right above us. ”
The Falcon 9 is a partially reusable two-stage rocket. The first stage, which houses nine of the SpaceX Merlin engines, does the initial heavy lifting of getting the rocket off the ground, while the second stage, with only a single Merlin engine, leads it into a parking lane.
The first stage can be sent back to Earth, and it’s this part of the rocket that you’ve probably seen land safely (or sometimes not!) On SpaceX’s drone ships. The second phase is usually abandoned to lap the Earth or burn up in the planet’s atmosphere.
This particular launch took place on March 4, sending another batch of SpaceX Starlink satellites into orbit, with the rocket’s first stage landing safely on Earth.
Jonathan McDowell, an astronomer at the Center for Astrophysics, tweeted a thread about the event, noting that this kind of debris return is not uncommon. “This is the 14th piece of space debris with a mass of more than a ton that has re-entered since January 1 of this year,” McDowell saidIn other words, about one a week. Plus, of course, many more smaller pieces. “
McDowell notes that it can be difficult to predict the timing of these re-entries. The debris breaks up high in the atmosphere, about 40 miles or 60 kilometers above the ground – that’s well above the cruising altitude of commercial flights (about 12 kilometers up). But the combination of headwinds in Earth’s upper atmosphere and the speed of travel (the debris moving at about 17,000 mph) makes it difficult to predict exactly when and where it will come in again.
The Falcon 9’s second stage of the Starlink launch on March 4 failed to cause a deorbit combustion and is now returning to orbit after 22 days. Its return was observed from the Seattle area at approximately 0400 UTC on March 26. pic.twitter.com/FQrBrUoBHh
– Jonathan McDowell (@ planet4589) March 26, 2021
4) But remember it’s going 17,000 mph, so a 5-hour time uncertainty means a location uncertainty of 85,000 miles (53,000 km). That’s more than a whole loop around the Earth. Therefore, we couldn’t say in advance that it would be the Seattle area that would see the return.
– Jonathan McDowell (@ planet4589) March 26, 2021
Seattle’s National Weather Service (NWS) also identified the bright lights like debris from a Falcon 9 second stage. The NWS noted that the rate at which such debris comes back is much slower than that of meteor showers, which are moving at speeds in excess of 45,000 mph.
Such re-entries are generally safe, burning up all missile components and material in the atmosphere. As Seattle’s NWS tweeted, “There are NO expected impacts on the ground in our region at this time.”
At this point, it looks like the only lasting effect will be a lot of fantastic footage, like the video below: