The Sloan Great Wall: Largest Known Structure
7.11.2007

What is the largest structure known? The answer might depend on how one defines "structure." A grouping of galaxies known as the Sloan Great Wall was discovered in the Sloan Digital Sky Survey and is a leading candidate.

Black Holes in Merging Galaxies
29.05.2010

Violent galaxy mergers can feed supermassive black holes. Theoretically, the result is intense emission from regions near the supermassive black holes, creating the some of the most luminous objects in the universe. Astronomers dub these Active Galactic Nuclei, or just AGN.

Sharpless 308: Star Bubble
24.12.2013

Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (Canis Major) and covers slightly more of the sky than a Full Moon.

Molecular Cloud Barnard 68
13.12.2014

Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars.

Satellites Behind Pinnacles
14.06.2022

What are all those streaks across the background? Satellite trails. First, the foreground features picturesque rock mounds known as Pinnacles. Found in the Nambung National Park in Western Australia, these human-sized spires are made by unknown processes from ancient sea shells (limestone). Perhaps more eye-catching, though, is the sky behind.

X Ray Rings Around a Gamma Ray Burst
17.10.2022

Why would x-ray rings appear around a gamma-ray burst? The surprising answer has little to do with the explosion itself but rather with light reflected off areas of dust-laden gas in our own Milky Way Galaxy.

Mir is 10
10.03.1996

The first module of the Russian Space Agency's Mir Space Station was launched into orbit 10 years ago (on February 20, 1986). Mir has since been substantially expanded in orbit by adding additional modules including the Kvant Astrophysics Module (1987) and recently a docking module.

The Ion Tail of Comet Hyakutake
19.03.1996

This picture of Comet Hyakutake was taken on March 14, 1996. Structure in the ion tale of Comet Hyakutake is now clearly visible. An ion tale forms as a comet nears the Sun. Sunlight causes gas and dust to boil off the comet's solid nucleus.

Galaxies in the GOODS
25.06.2003

This tantalizing view of galaxies scattered near and far is part of the Hubble Space Telescope's contribution to the GOODS - the Great Observatories Origins Deep Survey project. The GOODS' goal is to study...

The Hydra Cluster of Galaxies
12.05.2012

Two stars within our own Milky Way galaxy anchor the foreground of this cosmic snapshot. Beyond them lie the galaxies of the Hydra Cluster. In fact, while the spiky foreground stars are hundreds of light-years distant, the Hydra Cluster galaxies are over 100 million light-years away.