X-Ray Pleiades
18.03.1997

The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as a lovely and tantalizing grouping of stars in the constellation of Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight.

X Ray Saturn
12.03.2004

Above, the ringed planet Saturn shines in x-rays. Otherwise beyond the range of human vision, the eerie x-ray view was created by overlaying a computer generated outline of the gas giant's disk and ring system on a false-color picture of smoothed, reconstructed x-ray data from the orbiting Chandra Observatory.

Shadow Set
27.01.2005

A nearly full Moon and planet Earth's shadow set together in this scene captured Monday from snowy Mt. Jelm, home of the Wyoming Infrared Observatory. For early morning risers (and late...

VERITAS and Venus
8.11.2007

Early morning risers and late to bed astronomers have recently enjoyed bright planets in predawn skies, with brilliant Venus above the eastern horizon. On November 5, Venus was joined by the waning crescent Moon.

Hole in the Sun
28.08.2010

This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied...

The Magnificent Tail of Comet McNaught
17.11.2013

Comet McNaught, the Great Comet of 2007, grew a spectacularly long and filamentary tail. The magnificent tail spread across the sky and was visible for several days to Southern Hemisphere observers just after sunset. The amazing tail showed its greatest extent on long-duration, wide-angle camera exposures.

NGC 6823: Cloud Sculpting Star Cluster
8.10.2014

Star cluster NGC 6823 is slowly turning gas clouds into stars. The center of the open cluster, visible on the upper right, formed only about two million years ago and is dominated in brightness by a host of bright young blue stars.

The Sun Unleashed: Monster Filament in Ultraviolet
9.04.2018

One of the most spectacular solar sights is an explosive flare. In 2011 June, the Sun unleashed somewhat impressive, medium-sized solar flare as rotation carried active regions of sunpots toward the solar limb. That...

APOD: 2023 March 20 Б M1: The Expanding Crab Nebula
20.03.2023

Are your eyes good enough to see the Crab Nebula expand? The Crab Nebula is cataloged as M1, the first on Charles Messier's famous list of things which are not comets. In fact...

X-Rays from Comet LINEAR
1.08.2000

Why do comets emit X-rays? First discovered during the passing of Comet Hyakutake in 1996, the reason a cold comet would produce hot X-rays has since remained a mystery. On July 14, however...