NASA's 1,500 kg 'Neil Gehrels Swift Observatory' space telescope is scheduled to re-enter Earth's atmosphere on November 4 after operating for nearly 22 years. Extreme atmospheric heating will burn up most of the spacecraft, though some fragments may survive and reach the surface.
When Will It Re-enter?
According to NASA, the telescope is expected to enter the atmosphere around 2:00 PM IST, though there is an uncertainty window of approximately 11 hours.
Where is the Potential Impact Zone?
The potential re-entry zone spans between 20.6 degrees South and 20.6 degrees North latitude.
This area includes parts of Africa, Australia, India, Southeast Asia, and Central & South America.
In India, the footprint lies south of an imaginary line connecting Daman in the west to Cuttack in Odisha in the east. Cities like Mumbai, Hyderabad, Bengaluru, and Chennai fall within this latitude belt.
However, this does not imply a direct threat to these cities. The exact re-entry point will depend on the satellite's orientation during entry.
Will Debris Reach the Ground?
According to Brad Cenko, Chief Scientist for the NASA mission, some components might survive.
Astrophysicist Jonathan McDowell noted he would be surprised if more than 100 kg of material survives the descent.
Since nearly 70% of Earth is covered by oceans, the debris is most likely to fall into the sea. Brad Tucker from the Australian National University stated that the likelihood of human injury or structural damage is virtually zero.
Will ISRO Track the Re-entry?
ISRO operates the Multi-Object Tracking Radar (MOTR) at Sriharikota, which is capable of tracking late-stage orbital decays of satellites and rocket bodies. However, official confirmation on whether ISRO is actively tracking Swift has not been released.
A 22-Year Scientific Legacy
Launched on November 20, 2004, the spacecraft was originally designed for a 2-year primary mission under the name 'Swift Gamma-Ray Burst Explorer'.
It discovered over 2,000 gamma-ray bursts and studied nearly 1,400 supernovas.
Despite efforts to extend the mission and avoid an uncontrolled re-entry, the spacecraft is now making its final return.
