The Local Interstellar Cloud
11.04.2000

The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun.

Galaxies Away
21.08.1999

This striking pair of galaxies is far, far away ... about 350 million light-years from Earth. Cataloged as AM0500-620, the pair is located in the southern constellation Dorado. The background elliptical and foreground spiral galaxy are representative of two of the three major classes of galaxies which inhabit our Universe.

APOD: 2008 April 2- Globular Cluster M55 from CFHT
2.04.2008

The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. Only 20,000 light-years away in the constellation Sagittarius, M55 appears to earth-bound observers to be nearly 2/3 the size of the full moon.

Gemini Observatory North
15.10.2016

It does look like a flying saucer, but this technologically advanced structure is not here to deliver the wise extraterrestrial from the scifi classic movie The Day the Earth Stood Still. It is here to advance our knowledge of the Universe though.

Sigma Octantis and Friends
28.06.2018

South pole star Sigma Octantis (of the constellation Octans) is on the left of this starry expanse spanning over 40 degrees across far southern skies. You'll have to look hard to find it, though.

Vela Supernova Remnant Mosaic
10.01.2019

The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. Seen toward colorful stars near the northwestern edge of the constellation Vela (the Sails), the 16 degree wide, 200 frame...

Cygnus Mosaic 2010 2020
11.02.2021

In brush strokes of interstellar dust and glowing gas, this beautiful skyscape is painted across the plane of our Milky Way Galaxy near the northern end of the Great Rift and the constellation Cygnus the Swan.

Chamaeleon Dark Nebulas
17.01.2022

Sometimes the dark dust of interstellar space has an angular elegance. Such is the case toward the far-south constellation of Chamaeleon. Normally too faint to see, dark dust is best known for blocking visible light from stars and galaxies behind it.

Mu Cephei
12.10.2023

Mu Cephei is a very large star. An M-class supergiant some 1500 times the size of the Sun, it is one of the largest stars visible to the unaided eye, and even one of the largest in the entire Galaxy.

Nearby Spiral Galaxy NGC 4945
12.04.1999

For such a close galaxy, NGC 4945 is easy to miss. NGC 4945 is a spiral galaxy in the Centaurus Group of galaxies, located only six times farther away than the prominent Andromeda Galaxy. The thin disk galaxy is oriented nearly edge-on, however, and shrouded in dark dust.