Number of visible stars drastically falling, warns study, as ‘skyglow’ affects night sky

The number of visible stars is shrinking due to skyglow  (PA Archive)
The number of visible stars is shrinking due to skyglow (PA Archive)

The number of visible stars at night that can be seen with the naked eye is falling because of “skyglow”, which is the brightness from artificial light.

Skyglow has steadily increased since 2011. This has had a major impact on the environment, limiting human observation of both stars and the Milky Way.

Not only does it restrict stargazing, but also changes the overall appearance of the sky at night.

Why are stars disappearing from view?

It has been reported that 18 years ago the human eye could see about 250 stars in the night sky. But as of today, only about 100 stars are visible. Due to high levels of pollution and the effect of urban lighting, the night sky is brightening, and making stars disappear.

Artificial lighting that escapes into the sky causes it to glow, preventing humans and animals from seeing the stars.

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Research on the decline of stars’ visibility caused by skyglow

Dr Christopher Kyba, a scientist from the German Research Centre for Geosciences in Potsdam, and colleagues published their discovery in the journal Science. The study is a culmination of research over the past 12 years and clearly shows how pollution levels and skyglow are damaging our view of the night sky.

According to the research, the sky is brightening at different rates around the world. Europe is at 6.5 per cent a year and North America at 10.4 per cent a year. As well as humans many nocturnal animals are feeling the effect and some insect populations are in decline.

Fabio Falchi and Salvador Bará, who are light pollution researchers, commented on the study, saying: “Looking at the International Space Station’s images and videos of the Earth at night, people generally are struck by the ‘beauty’ of city lights, as if they were lights on a Christmas tree.

“They do not perceive that these are images of pollution. It is like admiring the beauty of the rainbow colours that gasoline produces in water and not recognising that it is chemical pollution.”

Dr Kyba offers some hope and said: “It does not need to be this way. There’s a lot of room for improvement – if you light more carefully, you should be able to reduce skyglow, whilst still lighting the ground.”

“And remember that light pollution is wasted energy. We’re continuing to put that light energy into the atmosphere, and maybe that’s not what we should be doing,” he added.