X For Andromeda
21.01.2000

A big beautiful spiral galaxy 2 million light-years away, Andromeda (M31) has long been touted as an analog to the Milky Way, a distant mirror of our own galaxy. The popular 1960s British sci-fi series, A For Andromeda, even postulated that it was home to another technological civilization that communicated with us.

APOD: 2024 December 17 Б Near to the Heart Nebula
17.12.2024

What excites the Heart Nebula? First, the large emission nebula on the upper left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light emitted by its most prominent element, hydrogen, but this long-exposure image was also blended with light emitted by sulfur (yellow) and oxygen (blue).

Comet SWAN Outburst
28.10.2006

Near its closest approach to planet Earth, comet SWAN (C/2006 M4) brightened unexpectedly earlier this week, becoming visible to naked-eye observers under dark night skies. Telescopic observers also noticed dramatic changes in the comet's colorful coma and tail, seen in this view recorded on October 25th.

A Telescopic View of Erupting Comet Holmes
29.10.2007

What's happened to Comet Holmes? A normally docile comet discovered over 100 years ago, Comet 17P/Holmes suddenly became nearly one million times brighter last week, possibly over just a few hours. In astronomical...

Along the Western Veil
19.09.2019

Delicate in appearance, these filaments of shocked, glowing gas, are draped across planet Earth's sky toward the constellation of Cygnus. They form the western part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star.

The Milky Way's Gamma-Ray Halo
5.11.1997

Our Milky Way galaxy appears to be surrounded by a halo of gamma rays. Gamma rays are the most energetic form of electromagnetic radiation, with more than a hundred thousand times the energy of visible light, but known gamma-ray sources don't account for the diffuse distribution of this high-energy glow.

Along the Western Veil
6.09.2018

Delicate in appearance, these filaments of shocked, glowing gas, are draped across planet Earth's sky toward the constellation of Cygnus. They form the western part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star.

Along the Western Veil
4.04.2014

Delicate in appearance, these filaments of shocked, glowing gas, draped in planet Earth's sky toward the constellation of Cygnus, make up the western part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star.

APOD: 2026 January 7 Б Simeis 147: The Spaghetti Nebula Supernova Remnant
7.01.2026

Its popular nickname is the Spaghetti Nebula. Officially cataloged as Simeis 147 and Sharpless 2-240, it is easy to get lost following the looping and twisting filaments of this intricate supernova remnant. Seen toward...

Hydrogen Trifid
28.08.1998

Clouds of glowing hydrogen gas mingle with dark dust lanes in the Trifid Nebula, a star forming region in the constellation Sagittarius. In this and other similar emission nebulae, energetic ultraviolet light from an embedded hot young star strips electrons from the surrounding hydrogen atoms.