A NASA space telescope is expected to return to Earth this week, with parts of India among the regions that could potentially lie within its debris zone.
The Neil Gehrels Swift Observatory, a space telescope launched in November 2004, is expected to re-enter Earth’s atmosphere on November 4. According to NASA, the predicted re-entry time is around 2 pm IST, although the event has an estimated 11-hour window.
The spacecraft weighs approximately 1.5 tonnes. Most of it is expected to burn up as it passes through the atmosphere, but some components could survive and reach the ground.
NASA estimates that the telescope’s re-entry zone lies between 20.6 degrees north and 20.6 degrees south latitude. This creates a broad band across parts of Africa, Australia, India, Southeast Asia and Central and South America.
Within India, the band covers areas south of an imaginary line running roughly from Daman on the western coast to Cuttack in Odisha. Mumbai, Hyderabad, Bengaluru and Chennai fall within this broad region, while Delhi, Kolkata and much of northern India lie outside it.
However, being within the latitude band does not mean that these cities are directly in the path of falling debris. The actual re-entry location will depend on the telescope’s position when it enters the atmosphere.
Experts believe that most of the telescope will disintegrate during atmospheric re-entry. Some dense components, including parts made of tungsten, may survive the intense heat.
Astrophysicist Jonathan McDowell told Gizmodo that he would be surprised if 100 kilograms of the telescope’s 1,500-kilogram mass survived re-entry.
Experts also believe that any surviving debris is more likely to fall into the ocean, given that a large majority of Earth’s surface is covered by water.
The chances of debris from the telescope damaging infrastructure or injuring someone are considered extremely low.
AccuWeather, citing NASA, reported that the estimated risk of harm to a person on Earth is approximately 1 in 2,100. While parts of several continents fall within the possible re-entry zone, the precise location of any surviving debris remains uncertain.
The Swift Observatory was launched on November 20, 2004, for a mission originally planned to last just two years.
Over its 22-year journey, the telescope observed more than 2,000 gamma-ray bursts and 1,400 supernovae. It also helped scientists study black holes, comets and other cosmic phenomena.
NASA’s attempts to save the ageing telescope and boost its orbit were unsuccessful. Its return to Earth marks the end of a mission that far exceeded its original lifespan.