Coronal Hole
7.02.2002

This ominous, dark shape sprawling across the face of the active Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space.

Maximum Sun
1.03.2001

Astronomers recently witnessed an astounding, large scale solar event as the Sun's north and south magnetic poles changed places! But, this complete solar magnetic field flip was actually anticipated. It occurs every 11 years during the maximum of the solar activity cycle.

Sun Storm: A Coronal Mass Ejection
10.01.2016

What's happening to our Sun? Another Coronal Mass Ejection (CME)! The Sun-orbiting SOHO spacecraft has imaged many erupting filaments lifting off the active solar surface and blasting enormous bubbles of magnetic plasma into space.

Solar Flare in the Gamma ray Sky
15.03.2012

What shines in the gamma-ray sky? The answer is usually the most exotic and energetic of astrophysical environments, like active galaxies powered by supermassive black holes, or incredibly dense pulsars, the spinning remnants of exploded stars.

Equinox 1
30.03.2001

Twice a year, at the Spring and Fall equinox, the Sun rises due east. In an emphatic demonstration of this celestial alignment, photographer Joe Orman recorded this inspiring image of the Sun rising exactly along the east-west oriented Western Canal, in Tempe, Arizona, USA.

Angry Sun Erupting
14.03.2012

It's one of the baddest sunspot regions in years. Active Region 1429 may not only look, to some, like an angry bird -- it has thrown off some of the most powerful flares and coronal mass ejections of the current solar cycle.

A Total Solar Eclipse of Saros 145
11.08.2017

A darkened sky holds bright planet Venus, the New Moon in silhouette, and the shimmering corona of the Sun in this image of a total solar eclipse. A composite of simultaneous telephoto and wide angle frames it was taken in the path of totality 18 years ago, August 11, 1999, near Kastamonu, Turkey.

In Green Company: Aurora over Norway
9.11.2020

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display.

APOD: 2023 January 22 Б In Green Company: Aurora over Norway
22.01.2023

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display.

Aurora at Midnight
5.05.1998

What's happening behind those trees? Aurora. This picture was taken at midnight near Fairbanks, Alaska, and captures familiar trees, common clouds, and a glowing sky markedly different than a sunset. Particularly strange is the green auroral ring caused by ionized oxygen high in the Earth's atmosphere.