Gemini Stars Pollux and Castor
15.05.2017

Who are the twins of Gemini? It terms of astronomical objects, the famous constellation is dominated by two bright stars: Pollux (left) and Castor (right). Pictured, the two stars stand out because they are so bright, so close together both in angle and brightness, but so different in color.

Orion in Red and Blue
13.10.2018

When did Orion become so flashy? This colorful rendition of part of the constellation of Orion comes from red light emitted by hydrogen and sulfur (SII), and blue-green light emitted by oxygen (OIII). Hues...

Mercurys Sodium Tail
7.07.2020

What is that fuzzy streak extending from Mercury? Long exposures of our Solar System's innermost planet may reveal something unexpected: a tail. Mercury's thin atmosphere contains small amounts of sodium that glow when excited by light from the Sun. Sunlight also liberates these molecules from Mercury's surface and pushes them away.

NGC 4565: Galaxy on Edge
16.05.2021

Is our Milky Way Galaxy this thin? Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices.

APOD: 2023 May 3 Б Centaurus A: A Peculiar Island of Stars
2.05.2023

Galaxies are fascinating. In galaxies, gravity alone holds together massive collections of stars, dust, interstellar gas, stellar remnants and dark matter. Pictured is NGC 5128, better known as Centaurus A. Cen A is the fifth brightest galaxy on the sky and is located at a distance of about 12 million light years from Earth.

APOD: 2025 May 14 Б NGC 1360: The Robins Egg Nebula
13.05.2025

This pretty nebula lies some 1,500 light-years away, its shape and color in this telescopic view reminiscent of a robin's egg. The cosmic cloud spans about 3 light-years, nestled securely within the boundaries of the southern constellation of the Furnace (Fornax).

APOD: 2025 August 19 Б Giant Galaxies in Pavo
18.08.2025

Over 500,000 light years across, NGC 6872 (bottom left) is a truly enormous barred spiral galaxy. At least 5 times the size of our own large Milky Way, NGC 6872 is the largest known spiral galaxy.

APOD: 2026 June 11 Б The Mermaid Nebula Supernova Remnant
10.06.2026

Could the Little Mermaid turn into stardust instead of seafoam? It would seem so in this beautiful nebula. The featured image shows the Mermaid Nebula, also known as the Betta Fish Nebula, which is part of the G296.5+10.0 Supernova Remnant.

Cas A Supernova Remnant in X Rays
24.08.2002

The complex shell of a star seen to explode 300 years ago is helping astronomers to understand how that star exploded. This Chandra Observatory image of supernova remnant Cassiopeia A (Cas A) shows unprecedented detail in three x-ray colors.

M74: The Perfect Spiral
24.05.2003

If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 30 million light-years away toward the constellation Pisces, NGC 628 or M74 presents a gorgeous face-on view to earthbound astronomers.