Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2023 August 15
A body of water is seen in front of a night sky. The
water reflects the sky. In the sky, on the right are green
aurora. In the center is an orange plume. On the right
are three while plumes. 
Please see the explanation for more detailed information.

A Triply Glowing Night Sky over Iceland
Credit & Copyright: Wioleta Gorecka; Text: Natalia Lewandowska (SUNY Oswego)

Explanation: The Sun is not the quiet place it seems. It expels an unsteady stream of energetic electrons and protons known as the solar wind. These charged particles deform the Earth's magnetosphere, change paths, and collide with atoms in Earth's atmosphere, causing the generation of light in auroras like that visible in green in the image left. Earth itself is also geologically active and covered with volcanoes. For example, Fagradalsfjall volcano in Iceland, seen emitting hot gas in orange near the image center. Iceland is one of the most geologically active places on Earth. On the far right is the Svartsengi geothermal power plant which creates the famous human-made Blue Lagoon, shown emitting white gas plumes. The featured composition therefore highlights three different sky phenomena, including both natural and human-made phenomena.

Tomorrow's picture: a cosmic embrace

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