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Light pollution from satellites, space waste poses risk to astronomy

WION Web Team
New Delhi, Delhi, IndiaUpdated: Mar 31, 2021, 07:03 PM IST

In an undated image from NASA, the center of the Milky Way, viewed by the Hubble space telescope. Photograph:(Twitter)

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The European Space Agency (ESA) said that more than 9,200 tonnes of space objects present in the Earth's orbit, that include defunct satellites

Artificial satellites and space waste orbiting the Earth can make the night sky brighter, researchers have found, warning that light pollution from these could affect astronomers work to study the universe. 

The European Space Agency (ESA) said that more than 9,200 tonnes of space objects present in the Earth's orbit, that include defunct satellites, reports The Guardian. 

Such objects not just capable of light pollution, but also poses a collision risk. 

Scientists in the Monthly Notices of the Royal Astronomical Society detail how sunlight that is reflected and scattered from space objects can look like streaks in observations made by telescopes from the ground. 

"Because the streaks are often comparable to or brighter than objects of astrophysical interest, their presence tends to compromise astronomical data and poses the threat of irretrievable loss of information," the researchers wrote. 

They also said, "when observed with relatively low-sensitivity detectors like the unaided human eye, or with low-angular-resolution photometers, their combined effect is that of a diffuse night sky brightness component, much like the unresolved integrated starlight background of the Milky Way."

According to their calculations, the glow could rise up to 10 per cent of the natural sky brightness, a light pollution level earlier set by the International Astronomical Union (IAU) as being the limit that is acceptable at astronomical observatory regions. 

Though the scientists stress that natural levels of brightness have their own challenges, they said the current situation could become worse once more satellites, including "mega-constellations", are launched.