By Ahmed Abdelsalam
NASA's Neil Gehrels Swift Observatory, launched in 2004, is expected to re-enter Earth's atmosphere on Wednesday, burning up in an uncontrolled descent. The U.S. Space Force predicts the 3,200-pound spacecraft will hit the atmosphere around 3:30 a.m. EST on November 4.
Most of the satellite will burn up, but some components may survive. NASA says the risk of harm to anyone on the ground is approximately 1 in 2,100. Surviving fragments would be limited to latitudes between 20.6 degrees south and 20.6 degrees north.
Uncontrolled Re-entry Expected
The observatory can no longer steer or observe. NASA and the Space Force will continue monitoring and updating predictions.
Two Decades of Gamma-Ray Burst Science
Designed for a two-year mission, Swift spent 20 years studying cosmic gamma-ray bursts, the most powerful explosions since the Big Bang. It detected and tracked more than 2,000 such bursts, which occur about once daily and last from milliseconds to hundreds of seconds. Scientists still debate their origins, theorizing they may signal the birth of a black hole or the collision of neutron stars.
Recent Discovery of Wandering Black Hole
In July, Swift observed a "tidal disruption event" where a wandering supermassive black hole shredded a star on the outskirts of a galaxy. The event outshone its host galaxy in ultraviolet light, radiating with the energy of about 10 billion suns. The observation helped reveal otherwise invisible black holes drifting from galactic cores.
Failed Rescue Attempt
NASA attempted to boost Swift into a higher orbit last year using a private contractor, but the mission failed after the spacecraft could not rendezvous. Last month, with the observatory orbiting about 171 miles above Earth, controllers commanded it to end operations in preparation for re-entry.
Legacy of Discovery
NASA said Swift broadened understanding of a wide range of cosmic phenomena, from active galaxies and stellar X-ray flares to supernovae, comets, and asteroids in our solar system.
