The Swift Observatory Is Dropping Back to Earth This Week. Here’s What to Know

The Neil Gehrels Swift Observatory — formerly known as the Swift Gamma-Ray Burst Explorer — is in its final days. The space telescope was launched into orbit on Nov. 20, 2004. Almost 22 years to the day, it’s expected to come crashing back down on Wednesday. 

“Swift delivered an incredible, lasting return on investment for the nation, designed for a two-year primary mission but productive for more than 10 times as long,” Shawn Domagal-Goldman, director of the Astrophysics Division at NASA, said in a statement last month. 

NASA says the telescope should hit the atmosphere on Nov. 4 at around 3:30 a.m. ET, but the agency acknowledges an 11-hour window during which reentry is possible. That means it could come down in the middle of the night or the middle of the day. Most of the telescope is likely to burn up in orbit, with only a few components expected to reach Earth. 

The location where those components splash down depends entirely on when Swift reenters the atmosphere. However, NASA says that the surviving fragments are “limited between 20.6 degrees south latitude and 20.6 degrees north latitude.” On a map, that would create a band around the middle of the Earth terminating just above and just below the equator.

“The risk of harm coming to anyone on Earth is unlikely — approximately 1 in 2,100,” NASA said in a statement. “NASA and Space Force will continue to monitor the re-entry and update predictions.”

In preparation for Swift’s reentry, NASA shut down operations in late October after conducting its final observation on Oct. 20. It was orbiting at just 171 miles above Earth’s surface at that point, and the increased atmospheric drag prevented Swift from doing any further work. It was a bittersweet moment for those who worked on the project. 

Swift had a lifetime to remember

Swift’s initial mission was a runaway success and helped advance science’s understanding of gamma-ray bursts and their role in phenomena such as the birth of black holes and the history of the early universe. 

That initial mission ended on Nov. 4, 2004, but the observatory was doing so well that NASA left it up there to continue collecting data. Its name changed to the Neil Gehrels Swift Observatory on Jan. 10, 2018, in honor of pioneering NASA astrophysicist Neil Gehrels, who served as the agency’s chief of the Astroparticle Physics Laboratory from 1995 until his death in 2017. 

The space telescope was designed to help solve the mystery of gamma-ray bursts by rapidly detecting them, determining their sources and then further analyzing them for study back on Earth. It also enabled unique sampling to observe newly discovered objects only minutes after their light reached Earth, said Nousek.

The amount of science conducted using Swift’s data cannot be overstated. According to NASA, it scanned over 2,000 gamma-ray bursts, took 1.5 million images from its ultraviolet/optical telescope and sent home 12 TB of data. That data is showcased in an estimated 7,000 research papers, which averages out to just under one study per day over its 22-year run. 

“We hope Swift has set the standard for time domain astrophysics,” Nousek said. The space telescope also helped pioneer many policies that ultimately shaped those discoveries, such as making data immediately accessible and providing over 1,000 guest investigators with the opportunity to use Swift throughout its long life, according to Nousek.

It’s only a stroke of bad luck that kept the observatory from floating for even longer. NASA attempted a rescue of Swift over the summer of 2026. However, after a series of engineering difficulties and control issues, the attempt was abandoned, sealing Swift’s fate. NASA turned the instruments back on and kept recording data as long as possible.

Joe is a freelance journalist. It all started with a long-running affection for building his own PCs, which he did for the first time as a teenager. It evolved into a lifelong enjoyment of putting words on the internet about the subject. He’s written for CNET, PCMag, Mashable and SlashGear as a freelance writer, and worked as a Senior Editor at Android Authority for 10 years. When he’s not writing about tech and science, he’s learning the ins and outs of DIY home repair, gaming, playing his bass guitars and posting help on PC building and gaming subreddits. He is a staunch believer that orange juice should have pulp.

See full bio

See also  Cruise fined $500K for submitting a false report after last year’s pedestrian crash