Southern Saturn from Cassini
18.10.2004

What happens to Saturn's pervasive clouds at its South Pole? Visible in the above image of Saturn are bright bands, dark belts and a dark spot right over the South Pole. The above...

Rafting for Solar Neutrinos
27.10.1997

Where have all the neutrinos gone? A long time passing since this question was first asked (decades) as increasingly larger and more diverse detectors sensitive to neutrinos from our Sun have found fewer than expected. But why?

Lake Effect Snow on Earth
29.11.2004

What are those strange clouds stretching out from these lakes? The clouds are caused by cold air moving over a warm water and result in bands of lake-effect snow. The rising bands of moistened, warmed air that drop lake-effect snow alternate with clear bands of falling cold air.

An Iridescent Cloud Over Colorado
24.11.2007

Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. These clouds are formed of small water droplets of nearly uniform size.

Light Pillars from a Little Planet
31.01.2014

Eerie pillars of light ring the edges of this snowy little planet. Of course the little planet is planet Earth, shown in a nadir-to-zenith, around-the-horizon, little planet projection. The spherical panoramic image mosaic maps a view from Siilinjärvi in eastern Finland.

Saturns Moon Tethys
19.05.2002

Tethys is one of the larger and closer moons of Saturn. It was visited by both Voyager spacecraft - Voyager 1 in November 1980 and by Voyager 2 in August 1981. Tethys is now known to be composed almost completely of water ice. Tethys shows a large impact crater that nearly circles the planet.

Grey Sun Seething
7.01.1997

The Sun's surface is not smooth. It has thousands of bumps called granules and usually a few dark depressions called sunspots. Each of the numerous granules is the size of an Earth continent, but much shorter lived.

Ice Fishing for Cosmic Neutrinos
16.03.1999

In 1996, scientists melted a hole in the bottom of the world. In fact, several holes have been melted near the South Pole, and they are now being used as astronomical observatories. Astronomers with the Antarctic Muon and Neutrino Detector Array (AMANDA) lower into each vertical lake a string knotted with basketball-sized light detectors.

Sand Dunes Thawing on Mars
2.03.2008

What are these strange shapes on Mars? Defrosting sand dunes. As spring now dawns on the Northern Hemisphere of Mars, dunes of sand near the pole, as pictured above, are beginning to thaw. The carbon dioxide and water ice actually sublime in the thin atmosphere directly to gas.

A Lunar Corona over Turin
15.09.2019

What are those colorful rings around the Moon? A corona. Rings like this will sometimes appear when the Moon is seen through thin clouds. The effect is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud.