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.

2025 July 30
Four images of the Sun's edge are shown. In each
a loop of bright material is captured above the 
Sun's surface. 
Please see the explanation for more detailed information.

Coronal Loops on the Sun
Image Credit & Copyright: Andrea Vanoni

Explanation: Our Sun frequently erupts in loops. Hot solar plasma jumps off the Sun's surface into prominences, with the most common type of prominence being a simple loop. The loop shape originates from the Sun's magnetic field, which is traced by spiraling electrons and protons. Many loops into the Sun's lower corona are large enough to envelop the Earth and are stable enough to last days. They commonly occur near active regions that also include dark sunspots. The featured panel shows four loops, each of which was captured near the Sun's edge during 2024 and 2025. The images were taken by a personal telescope in Mantova, Italy and in a very specific color of light emitted primarily by hydrogen. Some solar prominences suddenly break open and eject particles into the Solar System, setting up a space weather sequence that can affect the skies and wires of Earth.

Jigsaw Universe: Astronomy Puzzle of the Day
Tomorrow's picture: open space


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Amber Straughn Specific rights apply.
NASA Web Privacy, Accessibility, Notices;
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.