APOD: 2025 March 5 Б Seven Sisters versus California
4.03.2025

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
12.07.2025

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.

NGC 4013 and the Tidal Stream
6.02.2008

Nearly 50 million light-years away in the constellation Ursa Major, NGC 4013 was long considered an isolated island universe. Seen edge-on, the gorgeous spiral galaxy was known for its flattened disk and central bulge of stars, cut by silhouetted dust lanes.

Gibbous Europa
15.12.2013

Although the phase of this moon might appear familiar, the moon itself might not. In fact, this gibbous phase shows part of Jupiter's moon Europa. The robot spacecraft Galileo captured this image mosaic during its mission orbiting Jupiter from 1995 - 2003.

Starburst Galaxy Messier 94
5.03.2025

Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the hunting dogs, Canes Venatici. A popular target for earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk.

Visitors Galaxy Gallery
27.04.2001

A tantalizing assortment of island universes is assembled here. From top left to bottom right are the lovely but distant galaxies M61, NGC 4449, NGC 4725, NGC 5068, NGC 5247, and NGC 5775/5774. Most are spiral galaxies more or less like our own Milky Way.

Hubble Telescope Maps Pluto
10.03.1996

No spacecraft from Earth has yet explored Pluto but astronomers have found ways of mapping its surface. A stunning map of this distant, diminutive planet, the first based on direct images, was revealed late last week in a Hubble Space Telescope press release.

GRB010222: Gamma Ray Burst, X Ray Afterglow
13.04.2001

A fading afterglow from one of the most powerful explosions in the universe is centered in this false color image from the spacebased Chandra X-ray Observatory. The cosmic explosion, an enormously bright gamma-ray burst (GRB), originated in a galaxy billions of light-years away and was detected by the BeppoSAX satellite on February 22.

Arp 220: Spirals in Collision
17.06.1997

Arp 220 is the brightest object in the local universe. But why does it shine so brightly? Arp 220 was cataloged as a peculiar galaxy in the 1960s. In the late 1980s, it was discovered to be an ultraluminous infrared galaxy and headed a list compiled from observations with the now-defunct IRAS satellite.