Dark Markings of the Sky
25.04.2009

Based on wide field photographs, American astronomer Edward Emerson Barnard cataloged the dark markings of the sky in the early 20th century. Barnard's markings are dark nebulae, interstellar clouds of obscuring gas and dust.

APOD Turns 17
16.06.2012

The first APOD appeared seventeen years ago today, on 1995 June 16. Although garnering only 14 page views on that day, we are proud to estimate that APOD has now served over one billion space-related images over the last 1.7 decades.

The Gamma Cygni Nebula
17.06.2022

Supergiant star Gamma Cygni is at the center of the Northern Cross. Near the plane of our Milky Way galaxy, that famous asterism flies high in northern summer night skies in the constellation Cygnus the Swan.

Globular Star Cluster 47 Tuc
18.05.2015

Globular star cluster 47 Tucanae is a jewel box of the southern sky. Also known as NGC 104, it roams the halo of our Milky Way Galaxy along with over 150 other globular star clusters.

The Blue Horsehead Nebula in Infrared
22.04.2018

The Blue Horsehead Nebula looks quite different in infrared light. In visible light, the reflecting dust of the nebula appears blue and shaped like a horse's head. In infrared light, however, a complex labyrinth of filaments, caverns, and cocoons of glowing dust and gas emerges, making it hard to even identify the equine icon.

Perseids Around the Milky Way
16.08.2020

Why would meteor trails appear curved? The arcing effect arises only because the image artificially compresses (nearly) the whole sky into a rectangle. The meteors are from the Perseid Meteor Shower that peaked last week.

Video: Powers of Ten
3.12.2022

How different does the universe look on very small scales? On very large scales? The most famous short science film of its generation gives breathtaking comparisons. That film, Powers of Ten, originally created in the 1960s, has been officially posted to YouTube and embedded here.

APOD: 2024 May 1 Б IC 1795: The Fishhead Nebula
30.04.2024

To some, this nebula looks like the head of a fish. However, this colorful cosmic portrait really features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia.

Cosmic Rays at Voyager 1
8.09.2012

Launched on a grand tour of the outer planets in 1977, by good fortune the twin Voyager spacecraft were also headed in the general direction of the Sun's motion relative to nearby stars. Thirty five years later, Voyager 1 appears to be nearing the boundary of the Sun's heliosphere and interstellar space.

Open Star Clusters M35 and NGC 2158
3.01.2013

Open clusters of stars can be near or far, young or old, and diffuse or compact. Found near the plane of our Milky Way galaxy, they contain from 100 to 10,000 stars, all of which formed at nearly the same time. Bright blue stars frequently distinguish younger open clusters.