What are Comet Tails Made Of?
26.03.1996

The tail of comet Hyakutake, visible in this recent color image, is composed of dust and gas driven off the icy comet nucleus by the Sun's heat and blown away by the solar wind. Bathed in solar ultraviolet light, the gas molecules break down and are excited, producing a characteristic glow.

Other Worlds and HD 38529
10.08.2000

After the latest round of discovery announcements, the list of known worlds of distant suns has grown to 50. While extrasolar planet discoveries are sure to continue, none - so far - points clearly to another planetary system like our own. Take, for example, the newly discovered parent star HD38529.

X Ray Cygnus A
10.11.2000

Amazingly detailed, this false-color x-ray image is centered on the galaxy Cygnus A. Recorded by the orbiting Chandra Observatory, Cygnus A is seen here as a spectacular high energy x-ray source. But it is actually more famous at the low energy end of the electromagnetic spectrum as one of the brightest celestial radio sources.

IC 443: Supernova Remnant and Neutron Star
2.06.2006

IC 443 is typical of the aftermath of a stellar explosion, the ultimate fate of massive stars. Seen in this false-color composite image, the supernova remnant is still glowing across the spectrum, from radio...

M106 Close Up
3.05.2012

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106.

Lyman Alpha Blob
2.07.2009

Dubbed a Lyman-alpha blob, an enormous cloud of hydrogen gas spans several hundred thousand light-years in this remarkable image (left), a composite of x-ray, optical, and infrared data from space and ground based observatories.

X Ray Cygnus A
5.10.2002

Amazingly detailed, this false-color x-ray image is centered on the galaxy Cygnus A. Recorded by the orbiting Chandra Observatory, Cygnus A is seen here as a spectacular high energy x-ray source. But it is actually more famous at the low energy end of the electromagnetic spectrum as one of the brightest celestial radio sources.

Messier 106
9.04.2021

Close to the Great Bear (Ursa Major) and surrounded by the stars of the Hunting Dogs (Canes Venatici), this celestial wonder was discovered in 1781 by the metric French astronomer Pierre Mechain. Later, it was added to the catalog of his friend and colleague Charles Messier as M106.

A Powerful Gamma Ray Burst
7.05.1998

Gamma-ray bursts are thought to be the most powerful explosions in the Universe, yet the cause of these high-energy flashes remains a mystery. Blindingly bright for space-based gamma-ray detectors the burst sources are so faint at visible wavelengths that large telescopes and sensitive cameras are required to search for them.

Keplers Supernova Remnant in X Rays
16.01.2007

What caused this mess? Some type of star exploded to create the unusually shaped nebula known as Kepler's supernova remnant, but which type? Light from the stellar explosion that created this energized cosmic cloud was first seen on planet Earth in October 1604, a mere four hundred years ago.