Red Nebula, Green Comet, Blue Stars
20.12.2018

This festively colored skyscape was captured in the early morning hours of December 17, following Comet Wirtanen's closest approach to planet Earth. The comet was just visible to the eye. The lovely green...

Wisps Surrounding the Horsehead Nebula
3.04.2019

The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas.

Horsehead and Orion Nebulas
9.05.2021

The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, they appear in opposite corners of the above stunning mosaic.

APOD: 2023 January 17 Б Unexpected Clouds Toward the Andromeda Galaxy
17.01.2023

Why are there oxygen-emitting arcs near the direction of the Andromeda galaxy? No one is sure. The gas arcs, shown in blue, were discovered and first confirmed by amateur astronomers just last year.

APOD: 2025 July 8 Б The Pleiades in Red and Blue
8.07.2025

If you have looked at the sky and seen a group of stars about the size of the full Moon, that's the Pleiades (M45). Perhaps the most famous star cluster in the sky, its brightest stars can be seen even from the light-polluted cities.

A Message from Earth
17.07.1997

What are these Earthlings trying to tell us? The above message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo Observatory - still the largest radio telescope in the world - a string of 1's and 0's representing the above diagram was sent.

Reflections on the 1970s
2.10.2003

The 1970s are often overlooked. In particular, the beautiful grouping of reflection nebulae NGC 1977, NGC 1975, and NGC 1973 in Orion are often overlooked in favor of the substantial stellar nursery better known as the Orion Nebula.

NGC 6888: A Tricolor Starfield
6.07.2006

NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. Near the center of this intriguing widefield view of interstellar gas clouds and rich star fields of the constellation Cygnus, NGC 6888 is about 5,000 light-years away.

NGC 1499: The California Nebula
24.09.2006

What's California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States.

The Horsehead Nebula
27.05.2007

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.