Irregular Galaxy Sextans A
14.11.1997

Grand spiral galaxies often seem to get all the glory. Their newly formed, bright, blue star clusters found along beautiful, symmetric spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too, like this lovely, gumdrop-shaped galaxy, Sextans A.

Aurora Over Clouds
10.09.2003

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.

Saturns Rings in Natural Color
23.07.2004

What colors are Saturn's rings? Recent images from the Cassini spacecraft now orbiting Saturn confirm that different rings have slightly different colors. The above image shows their sometimes-subtle differences in brightness and color. The rings reflect sunlight and so, even if they were perfectly reflecting, would appear the color of the Sun.

Missouri's Green Ribbon Sky
12.11.2004

The critics rave - "Amazing!", "Unbelievable!", "The best I've ever seen!" They aren't talking about a movie, though. Instead, even casual sky critics are remarking on November's stunning auroral displays, visible with surprising intensities well beyond the confines of high latitudes where auroral activity is normally observed.

Rays from an Unexpected Aurora
20.11.2005

This aurora was a bit of a surprise. For starters, on this Friday morning in August 2002, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to show an usual structure of green rays from some locations.

A Sun Pillar in Red and Violet
5.02.2006

Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada, two amateur photographers noticed an unusual red column of light rise mysteriously from a setting sun. During the next few minutes, they were able to capture the pillar and a photogenic sunset on film.

A View from the Zone
7.03.2014

Brilliant Venus and the central Milky Way rise in the early morning hours of March 1 in this sea and skyscape. The scene looks out from a beach at Sea Isle City, New Jersey, USA, planet Earth.

NGC 6334: The Cats Paw Nebula
18.06.2014

Nebulas are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius.

Plane Contrail and Sun Halo
4.04.2017

What's happened to the sky? Several common features of the daytime sky are interacting in uncommon ways. First, well behind the silhouetted hills, is the typically bright Sun. In front...

A Moon Dressed Like Saturn
16.03.2020

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.