Galaxy Cluster Abell 1689 Magnifies the Dark Universe
24.08.2010

What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster requires not only deep images from telescopes like the Hubble Space Telescope, but detailed computer modeling as well. To start, almost every fuzzy yellow patch in the above image is an entire galaxy.

The Dark River to Antares
16.05.2020

A dark river seems to flow through this sky from the horizon toward colorful clouds near red giant star Antares. Murky looking, the dark river is a dusty nebula obscuring background starlight near the central Milky Way, although the dark dust nebula contains mostly hydrogen molecular gas.

Dark Matter Ring Modeled around Galaxy Cluster CL0024 17
16.05.2007

How do we know that dark matter isn't just normal matter exhibiting strange gravity? A new observation of gravitationally magnified faint galaxies far in the distance behind a massive cluster of galaxies is shedding new dark on the subject.

A Pileus Iridescent Cloud Over Ethiopia
24.08.2011

Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts.

Crepuscular Rays Over Utah
31.08.2005

What could cause such rays of dark? Dark sky rays were caught in spectacular fashion earlier this month above Utah, USA. The cause is something surprisingly familiar: shadows. Clouds near the horizon can block sunlight from reflecting off air, making columns outward from the Sun appear unusually dark.

Crepuscular Rays Over Lake Michigan
11.08.2010

What could cause such rays of dark? Dark sky rays were caught in spectacular fashion earlier last month from Pentwater, Michigan, USA, looking west over Lake Michigan. The cause is something surprisingly familiar: shadows. Clouds near the horizon can block sunlight from reflecting off air, making columns outward from the Sun appear unusually dark.

Tycho s Supernova Remnant
30.04.2011

Tycho! Tycho! burning bright In the darkness of the night, What exploding white dwarf star Did frame thy remnant from afar, In the distant deep dark skies Under gaze of human eyes? Seen by mortals and their ma Named for one called Tycho Brahe.

LDN 988 and Friends
24.09.2015

Stars are forming in dark, dusty molecular cloud LDN 988. Seen near picture center some 2,000 light-years distant, LDN 988 and other nearby dark nebulae were cataloged by Beverly T. Lynds in 1962 using Palomar Observatory Sky Survey plates.

APOD: 2024 November 11 Б The Unusual Tails of Comet Tsuchinshan Atlas
11.11.2024

What created an unusual dark streak in Comet Tsuchinshan-Atlas's tail? Some images of the bright comet during mid-October not only caught its impressively long tail and its thin anti-tail, but a rather unexpected feature: a dark streak in the long tail.

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.