The Matter of Galaxy Clusters
24.10.2001

Situated over 2,000,000,000 (two billion) light-years from Earth, galaxies in cluster Abell 2390 (top) and MS2137.3-2353 (bottom) are seen in the right hand panels above, false-color images from the Hubble Space Telescope. Corresponding panels on the left reveal each cluster's x-ray appearance in images from the Chandra X-ray Observatory.

APOD: 2025 July 17 Б 3I/ATLAS
17.07.2025

Discovered on July 1 with the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert, System) survey telescope in Rio Hurtado, Chile, 3I/ATLAS is so designated as the third known interstellar object to pass through our Solar System It follows 1I/йOumuamua in 2017 and the comet 2I/Borisov in 2019.

In the Glare of Alpha Centauri
28.06.2012

The glare of Alpha Centauri, one of the brightest stars in planet Earth's night sky, floods the left side of this southern skyscape. A mere 4.3 light-years distant, Alpha Centauri actually consists of two component stars similar in size to the Sun, locked in a mutual orbit.

Small Star
20.11.1999

A dim double star system cataloged as Gliese 623 lies 25 light-years from Earth, in the constellation of Hercules. The individual stars of this binary system were distinguished for the first time when the Hubble Space Telescope's Faint Object Camera recorded this image in June 1994.

R Leporis: A Vampire's Star
31.10.2018

Better known as Hind's Crimson Star, R Leporis is a rare star in planet Earth's night sky. It's also a shocking shade of red. The star's discoverer, 19th century English...

First Horizon Scale Image of a Black Hole
1.05.2022

What does a black hole look like? To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas.

Grand Spiral Galaxy M81 and Arps Loop
16.04.2013

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy lies 11.8 million light-years away toward the northern constellation of the Great Bear (Ursa Major).

The Complex Ion Tail of Comet Lovejoy
20.01.2015

What causes the structure in Comet Lovejoy's tail? Comet C/2014 Q2 (Lovejoy), which is currently at naked-eye brightness and near its brightest, has been showing an exquisitely detailed ion tail. As the name...

LIGO Virgo GW170814 Skymap
28.09.2017

From around planet Earth three gravitational wave detectors have now reported a joint detection of ripples in spacetime, the fourth announced detection of a binary black hole merger in the distant Universe. The event...

Galaxies and the South Celestial Pole
1.01.2021

The South Celestial Pole is easy to spot in star trail images of the southern sky. The extension of Earth's axis of rotation to the south, it's at the center of all the southern star trail arcs.