starlink geomagnetic storm
As many as 40 Starlink satellites are currently falling out of the sky--the surprising result of a minor geomagnetic storm. SpaceX made the announcement yesterday:

"On Thursday, Feb. 3rd at 1:13 p.m. EST, Falcon 9 launched 49 Starlink satellites to low Earth orbit from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. ... Unfortunately, the satellites deployed on Thursday were significantly impacted by a geomagnetic storm on Friday, [Feb. 4th]."

Two days before launch a CME hit Earth's magnetic field. It was not a major space weather event. In fact, the weak impact did not at first spark any remarkable geomagnetic activity. However, as Earth passed through the CME's wake, some sputtering G1-class geomagnetic storms developed. It was one of these minor storms that caught the Starlink satellites on Feb. 4th.

Geomagnetic storms heat Earth's upper atmosphere. Diaphanous tendrils of warming air literally reached up and grabbed the Starlink satellites. According to SpaceX, onboard GPS devices detected atmospheric drag increasing "up to 50 percent higher than during previous launches."

"The Starlink team commanded the satellites into a safe-mode where they would fly edge-on (like a sheet of paper) to minimize drag," says SpaceX. "Preliminary analysis show the increased drag at the low altitudes prevented the satellites from leaving safe-mode to begin orbit raising maneuvers, and up to 40 of the satellites will reenter or already have reentered the Earth's atmosphere."

The Sociedad de Astronomia del Caribe apparently caught one of the reentries over Puerto Rico on Feb. 7th:


SpaceX says that the deorbiting satellites "pose zero collision risk with other satellites and by design demise upon atmospheric reentry — meaning no orbital debris is created and no satellite parts hit the ground."

Keep an eye on the night sky this week. You might catch a Starlink satellite burning up overhead.