Swift data trace gold and iodine on Earth to ancient dead-star collisions

Swift satellite turned toward gamma-ray bursts within seconds while texting scientists

Much of the gold in jewelry and the iodine in human bodies came from ancient collisions of dense dead stars, according to an NPR report on NASA’s Swift observatory. Brad Cenko, the mission’s principal investigator, described the connection in personal terms: “The precious metals in our jewelry - gold, platinum, silver. The iodine that’s in our bodies plays a really important biological role.” A lot of that material, correspondent Geoff Brumfiel reported, came from those ancient collisions.

Swift, Brumfiel reported, played a key role in studying the dead-star collisions, which led to gargantuan explosions that in turn forged many of the elements that eventually found their way to Earth. “We know that now thanks to Swift,” he reported.

Gamma-ray bursts themselves are incredibly powerful flashes of high-energy light that last just a few seconds, and astronomers never know when or where in the night sky one will appear, according to the report. “Keeping an eye on gamma ray bursts is a 24-hours-a-day, 365-days-a-year job,” said Kim Page, an astrophysicist at the University of Leicester in the U.K.

The job of keeping that constant watch fell, Brumfiel reported, to “a plucky little NASA satellite called Swift,” which got its name for what it could do. Within seconds of detecting a burst, Swift could turn its telescopes to look at where the burst came from while simultaneously alerting scientists on the ground below by sending a text to their cellphones.

Brumfiel reported that Page had last count of how many times Swift woke her to look at something, but that it never got old. “I gather from my colleagues that I am unusually cheery for somebody who’s been woken up at 3 o’clock in the morning,” Page said. “It’s still really thrilling to know that you’re one of the first people to see the data as they come in,” she said.

The data Swift gathered included images of some of the biggest explosions in the universe. Cenko said the amount of energy involved is wild. A gamma-ray burst radiates its energy in just seconds — “It’s radiating more energy in that period than the sun will in its entire lifetime,” he said. Brumfiel described such events as “unfathomably violent”: black holes shredding their neighbors and extremely dense dead stars colliding together.

Swift’s undoing, Brumfiel reported, came from “a star much closer to home.” The sun has become more volatile in recent years, the report said, and solar flares hitting Earth caused the atmosphere to swell; the added drag pulled the spacecraft out of orbit. Host Ailsa Chang introduced the segment by describing the space telescope as having “streaked back to Earth like a meteor” — what she called a blazing end to a mission that captured some of the brightest events in the universe. The report aired Wednesday, as the observatory reentered Earth’s atmosphere after two decades of gathering data.

Astronomers like Page will no longer receive the late-night calls alerting them to the universe’s biggest mysteries, according to the report. Page said the mission’s end feels like “losing one of the family.” “I’ve thought about Swift every day for 22 years,” she said.

Brumfiel reported that Page will have memories and images of thousands of objects from across the cosmos — the legacy of a mission that observed gamma-ray bursts, collisions of dense dead stars and some of the universe’s biggest explosions, according to the report.