I Zwicky 18: Young Galaxy
3.12.2004

The Milky Way is an ordinary 12 billion year old spiral galaxy, and even our middle-aged Sun is pushing 4.5 billion years. But all the stars in dwarf galaxy I Zwicky 18 are much younger.

Inside the Coma Cluster of Galaxies
28.02.2015

Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured above is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does.

The Colorful Clouds of Rho Ophiuchi
12.03.1996

The many spectacular colors of the Rho Ophiuchi (oh'-fee-yu-kee) clouds highlight the many processes that occur there. The blue regions shine primarily by reflected light. Blue light from the star rho Ophiuchi and nearby stars reflects more efficiently off this portion of the nebula than red light.

Comet Hyakutake and a Tree
10.04.1996

Comet Hyakutake is still visible as it continues its orbit around the Sun. The comet will brighten again in late April and early May. The above fascinating picture was taken with a three minute exposure. In the middle of the exposure, the photographer cleverly set off a flash, momentarily illuminating the foreground tree.

Jones Emberson 1
24.02.2023

Planetary nebula Jones-Emberson 1 is the death shroud of a dying Sun-like star. It lies some 1,600 light-years from Earth toward the sharp-eyed constellation Lynx. About 4 light-years across, the expanding remnant...

Across the Center of Centaurus A
29.11.2011

A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A. This image from the Hubble Space Telescope has been processed to present a natural color picture of this cosmic maelstrom.

Large Sunspots Now Crossing the Sun
10.07.2013

One of the largest sunspot regions in recent years is now crossing the Sun. This region of convoluted magnetic fields may well produce a solar flare that releases a cloud of energetic particles into the Solar System.

APOD: 2025 March 5 Б Seven Sisters versus California
5.03.2025

On the right, dressed in blue, is the Pleiades. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. The Pleiades contains over 3,000 stars, is about 400 light years away, and only 13 light years across.

APOD: 2025 July 13 Б Planetary Nebula Mz3: The Ant Nebula
13.07.2025

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?

Binary Black Hole in 3C 75
12.04.2006

The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years.