A Large Active Region Crosses the Sun
26.07.2004

An unexpectedly large sunspot region is now crossing the Sun. The active region is home to rivers of hot plasma, explosive flares, strong magnetic fields, a powerful Coronal Mass Ejection (CME), and a sunspot group so large it can be seen by the protected eye without magnification.

Sunspot at Sunset
8.01.2014

Sunsets may be the most watched celestial event, but lately sunsets have even offered something extra. A sunspot so large it was visible to the naked eye is captured in Swiss skies in this...

Red Sun Streaming
7.01.1997

The Sun is leaking. In fact, it is gushing: particles stream away from the Sun at hundreds of kilometers per second. Some of these particles strike the Earth and cause aurora. Most particles, however, either surround the Sun as a huge solar corona or glide into interstellar space as the solar wind.

Cloudy Night of the Northern Lights
30.09.2011

On September 26, a large solar coronal mass ejection smacked into planet Earth's magnetosphere producing a severe geomagnetic storm and wide spread auroras. Captured here near local midnight from Kvaløya island outside Tromsø in northern Norway, the intense auroral glow was framed by parting rain clouds.

Contemplating the Sky
13.08.2002

Have you contemplated your sky recently? Last night was a good one for midnight meditators at many northerly locations as meteors from the Perseid meteor shower frequently streaked through. The Perseid meteor shower has slowly been building to a crescendo but should continue to be rewarding tonight and into the week.

Airglow Ripples over Tibet
1.09.2014

Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured above. The unusual...

APOD: 2024 March 4 Б Light Pillars Over Inner Mongolia
4.03.2024

What's happening across that field? Pictured here are not auroras but nearby light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer can see a Sun pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere.

APOD: 2026 March 23 Б Light Pillars and Orion over Mohe
23.03.2026

What's happening at the end of that street? Pictured here are not auroras but light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer...

The Terraced Night
6.02.2014

Long after sunset on January 25 an unusually intense red airglow floods this south-looking skyscape. The scene was recorded with a long exposure using a digital camera over Yunnan Province in southwest China. At best faintly visible to the eye, the lingering airglow is due to chemiluminescence, the production of light through chemical excitation.

Contemplating the Sky
8.08.2004

Have you contemplated your sky recently? This week will be a good one for midnight meditators at many northerly locations as meteors from the Perseid meteor shower will frequently streaked through. The Perseid meteor shower has slowly been building to a crescendo and should peak on the nights of August 11 and 12.