NASA’s Neil Gehrels Swift Observatory, a space telescope that has spent about 22 years studying gamma-ray bursts and a wide range of other cosmic phenomena, is expected to burn up in Earth’s atmosphere after an attempt to rescue it failed. The observatory’s orbit gradually declined, and a rescue spacecraft launched in July began spinning out of control before reaching Swift. As Swift descended too far to track its astronomical targets, NASA halted science operations last week.
Astronomers are mourning the end of a mission that transformed the study of black holes, supernovae, comets and gamma-ray bursts, the most powerful explosions in the universe.
“We’re all definitely very sad. There’s definitely some sadness,” says Caryl Gronwall, head of Swift’s science operations team at Penn State University in University Park. Hannah Earnshaw, an astronomer at the California Institute of Technology in Pasadena, described the mission’s end as particularly “dramatic and tragic.”
Some researchers predict that Swift will re-enter Earth’s atmosphere on November 2nd. Most of the observatory will burn up, although a small amount of debris will likely reach the ocean.
Studying colliding stars
Swift was initially designed to observe gamma-ray bursts: incredibly bright, short-lived flashes of high-energy radiation. The observatory detected about 2,000 of these bursts and helped establish that some are produced when two neutron stars—the ultra-dense cores left behind by dead stars—collide.
In 2017, Swift observed the aftermath of a particularly significant neutron-star collision. Its observations helped show that such events produce heavy elements including gold and platinum.
A mission beyond its original purpose
Swift’s most notable achievements, however, came from research beyond its original assignment. Observations of supernovae and comets helped scientists understand how black holes produce powerful jets when they consume stars.
“The science portfolio has evolved and grown far beyond its original purpose,” said Brad Senko, Swift’s principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Source: www.nature.com
