{"id":42350,"date":"2023-02-21T10:24:14","date_gmt":"2023-02-21T10:24:14","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=116294"},"modified":"2023-02-21T11:32:40","modified_gmt":"2023-02-21T11:32:40","slug":"why-is-the-sky-blue","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/why-is-the-sky-blue\/","title":{"rendered":"Why is the sky blue?"},"content":{"rendered":"

What’s the scientific reason behind Earth’s sky appearing blue to the human eye? <\/p>

By Amy Arthur\n \t\t<\/p>

Published: Tuesday, 21 February 2023 at 12:00 am<\/p>

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When sunlight reaches Earth\u2019s atmosphere, it contains virtually every wavelength on the electromagnetic spectrum<\/a>.<\/p>\n

This includes all the colours of visible light, from the shorter waves of violet and blue, to the longer wavelengths of orange and red.<\/p>\n

When our eyes see all these wavelengths together, they look like pure white. But then why is the sky blue?<\/p>\n

As well as the sunlight, Earth\u2019s atmosphere contains molecules like nitrogen, oxygen and carbon dioxide, as well as particles of dust, water vapour and pollutants.<\/p>\n

Where the sunlight first reaches us, the upper atmosphere, it will meet and interact with the most abundant molecules in our air: nitrogen and oxygen.<\/p>\n

These molecules are small, and light at longer wavelengths manages to pass by nitrogen and oxygen without too much interference.<\/p>\n