GS Paper - III

Elon Musk’s Starlink satellites are impeding the work of astronomers, a study published in the journal Astronomy & Astrophysics found. Currently, the Starlink “constellation” comprises more than 6,300 working satellites orbiting Earth at an altitude of around 550 km. These satellites deliver high-speed internet to places which otherwise would not have access to it. At the same time, they also create “radio noise”, or unintended electromagnetic radiation (UEMR). This is what impedes the work of radio astronomers observing the sky from Earth.

Blinded by light

• Radio astronomy is a branch of astronomy that studies celestial objects at radio frequencies.
• Unlike optical telescopes that detect visible light, radio telescopes are designed to detect radio waves (which have higher wavelengths and lower frequencies) emitted by objects in space.
• But just like bright visible light can blind the observer — like the bright headlights of an approaching car — the same can also happen at radio frequencies. This is essentially why radio noise is a problem.
• For radio astronomers, observing while a satellite is in its field of view is like trying to see the faintest star visible to the naked eye next to a full Moon.

Need for regulation

• Things might get worse. The recent study found that Starlink’s second-generation satellites — which currently account for less than a third of the network — emit UEMR at levels 32 times brighter than its first-generation satellites.
• This is despite Starlink already running into trouble about the UEMR of its first-gen satellites.
• Moreover, as launching satellites becomes cheaper, some estimate that as many as 100,000 satellites could be orbiting Earth by 2030.
• The number was pegged at 11,330 in June 2023 by the United Nations Office for Outer Space Affairs (UNOOSA).
• Experts say that these developments signal the need for regulations for satellite operators, just like there exist regulations for radio pollution from ground-based electronic sources like cellphone towers.
• Currently, astronomers are largely reliant on forging good faith interactions with companies like Starlink, which put satellites into space.