Abell 2218: A Galaxy Cluster Lens
1.02.2000

Gravity can bend light. Almost all of the bright objects in this recently released Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. The cluster is so massive and so compact that its gravity bends and focuses the light from galaxies that lie behind it.

Dark Matter in a Simulated Universe
25.10.2020

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

3I/ATLAS Flyby
26.12.2025

Attention grabbing interstellar visitor 3I/ATLAS made its not-so-close flyby of our fair planet on December 19 at a distance of 1.8 astronomical units. That's about 900 light-seconds. This deep exposure captures the comet...

Dark Matter in a Simulated Universe
31.10.2021

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

Dark Matter in a Simulated Universe
31.10.2017

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

Ski Mars
1.04.1999

These brightly reflecting fields of snow or frost are on the slopes of a crater rim in the northern hemisphere of Mars. They are 500 meters or so long and have lasted through about eight months of the Red Planet's spring and summer weather.

Galaxy Wars: M81 versus M82
15.04.2006

In this stunning cosmic vista, galaxy M81 is on the left surrounded by blue spiral arms. On the right marked by massive gas and dust clouds, is M82. These two mammoth galaxies have been locked in gravitational combat for the past billion years.

APOD: 2024 October 20 Б Dark Matter in a Simulated Universe
20.10.2024

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

The Matter of the Bullet Cluster
15.01.2017

What's the matter with the Bullet Cluster? This massive cluster of galaxies (1E 0657-558) creates gravitational lens distortions of background galaxies in a way that has been interpreted as strong evidence for the leading theory: that dark matter exists within.

Galaxy Wars: M81 versus M82
24.03.2010

On the right, surrounded by blue spiral arms, is spiral galaxy M81. On the left, marked by red gas and dust clouds, is irregular galaxy M82. This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years.