11 Hour Star Trails
15.09.2006

Fix your camera to a tripod, lock the shutter open, and you can make an image of star trails - graceful concentric arcs traced by the stars as planet Earth rotates on its axis. Of course, the length of the star trails will depend on the exposure time.

Volcano and Aurora in Iceland
20.01.2002

Sometimes both heaven and Earth erupt. In Iceland in 1991, the volcano Hekla erupted at the same time that auroras were visible overhead. Hekla, one of the most famous volcanoes in the world, has erupted at least 20 times over the past millennium, sometimes causing great destruction.

Dueling Auroras
2.12.2001

Will it be curtains for one of these auroras? A quick inspection indicates that it is curtains for both, as the designation "curtains" well categorizes the type of aurora pattern pictured. Another (informal) type is the corona. The above auroras resulted from outbursts of ionic particles from the Sun during the last week of September.

The Secret of the Black Aurora
31.12.2001

What causes black aurora? These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the Earth has now likely found the secret: black auroras are actually anti-auroras.

Jupiter s Great X Ray Spot
28.02.2002

The Solar System's largest planet, gas giant Jupiter, is famous for its swirling Great Red Spot. In the right hand panel above, the familiar giant planet with storm system and cloud bands is shown in an optical image from the passing Cassini spacecraft.

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.

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.