Millions in Indonesia saw the sky turn blood red over the weekend.
Experts say the red skies were caused by smoke and haze from wildfires in the Pacific Rim region, which rose into the upper atmosphere.
This rare phenomenon is known as the Rayleigh Scattering effect.
The particles from the fire filter out blue and green wavelengths and disperse the longer wavelengths of red, orange and yellow to create the effect.
Some of the deepest red photos were taken at noon.
Ini sore bukan malam. Ini bumi bukan planet mars. Ini jambi bukan di luar angkasa. Ini kami yang bernafas dengan paru-paru, bukannya dengan insang. Kami ini manusia butuh udara yang bersih, bukan penuh asap.— Zuni Shofi Yatun Nisa (@zunishofiyn) September 21, 2019
Lokasi : Kumpeh, Muaro Jambi #KabutAsap #KebakaranHutanMakinMenggila pic.twitter.com/ZwGMVhItwi
If the sun is overhead and you look up, you will be looking in the line of the sun, so it would appear that more of the sky is red.
The phenomenon does not raise the air temperature, however.
This year’s haze levels have been some of the worst in years. The haze is caused by open burning in Indonesia and to a lesser extent, parts of Malaysia and India.
The burning usually peaks from July to October during Indonesia’s dry season. According to Indonesia’s national disaster agency, some 328,724 hectares of land had already been burnt in the first eight months of the year.
The last time the sky over Indonesia turned red was after the eruption of Mount Pinatubo in 1991, which colored the atmosphere for months. Source