The Solar Spectrum
23.04.2006

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

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.

Filaments of the Cygnus Loop
28.09.2020

What lies at the edge of an expanding supernova? Subtle and delicate in appearance, these ribbons of shocked interstellar gas are part of a blast wave at the expanding edge of a violent stellar explosion that would have been easily visible to humans during the late stone age, about 20,000 years ago.

The Medulla Nebula Supernova Remnant
18.01.2021

What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion.

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.

APOD: 2025 December 7 Б The Sun and Its Missing Colors
7.12.2025

It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Whale and the Hockey Stick
21.08.2009

NGC 4631 is a big beautiful spiral galaxy seen edge-on (top right) only 25 million light-years away towards the small northern constellation Canes Venatici. This galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others the popular moniker of The Whale Galaxy.

The Red Spider Planetary Nebula
19.04.2017

Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star.

Saturn at Night
2.11.2024

Saturn is bright in Earth's night skies. Telescopic views of the outer gas giant planet and its beautiful rings often make it a star at star parties. But this stunning view of Saturn's rings and night side just isn't possible from telescopes in the vicinity of planet Earth.