Nebula Nova Cygni Turns On
16.12.1996

Old photographs show no evidence of the above nebula. In 1992, a white dwarf star in Cygnus blew off its outer layers in a classical nova explosion: an event called Nova Cygni 1992. Light flooded the local interstellar neighborhood, illuminated this existing gas cloud, excited the existing hydrogen, and hence caused the red emission.

The Red Rectangle
2.11.1995

The unusual geometry of this stellar nebula creates somewhat of a mystery. At the nebula's center is a young binary star system that probably created the nebula, but how? This type of nebula shows a "bipolar flow" which carries a significant amount of mass away from the central stars.

A Milky Way Band
24.02.1999

Most bright stars in our Milky Way Galaxy reside in a disk. Since our Sun also resides in this disk, these stars appear to us as a diffuse band that circles the sky. The above panorama of a southern band of the Milky Way's disk was taken from Australia.

Star Cluster in the Rosette Nebula
22.05.1996

Embedded in the center of the colorful and photogenic Rosette Nebula is a bright, young open cluster. The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms.

Comet Hyakutake and a Solar Flare
17.05.1996

A rare coincidence was recently captured by the orbiting SOHO spacecraft. During the closest approach to the Sun of Comet Hyakutake on May 1, SOHO photographed the comet. By accident -- during the time this photograph was being taken -- a solar flare was being ejected from the Sun.

Air Pollution Earth
9.07.2001

Where on Earth is the air most polluted? Recently released images from the Terra satellite show not only areas of high pollution, but also how polluted air moves. In the above image, locations of higher air pollution are shown in red. The pollutant tracked is carbon monoxide (CO) at a height of about 5 kilometers.

X-Raying the Moon
31.08.1995

Above is a picture of the Moon taken in X-rays by the Roentgen Observatory Satellite ROSAT in 1990. This famous picture shows three distinct regions: a bright X-ray sky, a bright part of the Moon, and a relatively dark part of the Moon.

The Dark River to Antares
9.08.2004

Connecting the Pipe Nebula to the bright star Antares is a flowing dark cloud nicknamed the Dark River. The murkiness of the Dark River is caused by absorption of background starlight by dust, although the nebula contains mostly hydrogen and molecular gas.

The Cygnus Loop
8.08.1998

15,000 years ago a star in the constellation of Cygnus exploded -- the shockwave from this supernova explosion is still expanding into interstellar space! The collision of this fast moving wall of gas with...

The Cygnus Loop
3.08.1997

15,000 years ago a star in the constellation of Cygnus exploded -- the shockwave from this supernova explosion is still expanding into interstellar space! The collision of this fast moving wall of gas with...