Pillar at Sunset
6.03.2010

Reddened light from the setting Sun illuminates the cloud banks hugging this snowy, rugged terrain. Inspiring a moment of quiet contemplation, the sunset scene included a remarkable pillar of light that seemed to connect the clouds in the sky with the mountains below.

Neptune: Big Blue Giant
21.02.1998

This picture was taken by the Voyager 2 spacecraft in 1989 - the only spacecraft ever to visit Neptune. Neptune will be the farthest planet from the Sun until 1999, when the elliptical orbit of Pluto will cause it to once again resume this status.

Dueling Auroras
7.08.2005

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.

Rhea: Saturns Second Largest Moon
5.12.1999

Rhea is the second largest moon of Saturn, behind Titan, and the largest without an atmosphere. It is composed mostly of water ice, but has a small rocky core. Rhea's rotation and orbit are locked together (just like Earth's Moon) so that one side always faces Saturn.

NGC 6369: A Donut Shaped Nebula
18.05.1998

Why isn't the star in the center of the nebula? NGC 6369 appears to be a fairly ordinary planetary nebula. It can be seen with a good telescope in the constellation of Ophiuchus. The gas expelled by the central star is bunched in the shape of a donut or cylinder.

Dark Sky, Bright Sun
14.02.1999

In low Earth orbit there is not enough atmosphere to diffuse and scatter sunlight, so shadows are black and the sky is dark - even when the Sun shines. The harsh lighting produced this dramatic...

Neptune: Big Blue Giant
17.08.1995

This picture was taken by the Voyager 2 spacecraft in 1986 - the only spacecraft ever to visit Neptune. Neptune will be the farthest planet from the Sun until 1999, when the elliptical orbit of Pluto will cause it to once again resume this status.

Astro 1 In Orbit
17.08.1997

In December of 1990, the Space Shuttle Columbia carried an array of astronomical telescopes high above the Earth's obscuring atmosphere to observe the Universe at ultraviolet and x-ray wavelengths. The telescopes, known...

Aurora Over Alaska
4.03.1998

Higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Aurora rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from solar electrons and protons striking molecules in the Earth's atmosphere.

Carl Sagan 1934-1996
26.12.1996

Carl Sagan died last Friday at the age of 62. Sagan was the world's most famous astronomer. Among his many activities as a scientist, he contributed to the discovery that the atmosphere...