The Supermassive Black Holes of NGC 6240
28.11.2002

The Hubble optical image on the left shows NGC 6240 in the throes of a titanic galaxy - galaxy collision 400 million light-years away. As the cosmic catastrophe plays out, the merging galaxies spew forth distorted tidal tails of stars, gas, and dust and undergo frantic bursts of star formation.

A Redshift Lookup Table for our Universe
8.04.2013

How far away is "redshift six"? Although humans are inherently familiar with distance and time, what is actually measured for astronomical objects is redshift, a color displacement that depends on exactly how energy density has evolved in our universe.

Cartwheel Of Fortune
18.01.2006

By chance, a collision of two galaxies has created a surprisingly recognizable shape on a cosmic scale - The Cartwheel Galaxy. The Cartwheel is part of a group of galaxies about 400 million light years away in the constellation Sculptor (two smaller galaxies in the group are visible below and left).

Saturn s Ancient Rings
17.12.2007

How old are Saturn's rings? No one is quite sure. One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn.

The Local Fluff
24.09.2013

The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun.

Double Cluster in Perseus
23.01.2014

This lovely starfield spans some seven full moons (about 3.5 degrees) across the heroic northern constellation of Perseus. Just right of center it holds the famous pair of open or galactic star clusters, h and Chi Perseii.

M46 Plus Two
17.04.2015

Galactic or open star clusters are young. These swarms of stars are born together near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are ejected by galactic tides and gravitational interactions. In fact, this bright open cluster, known as M46, is around 300 million years young.

Solar Granules at Record High Resolution
3.02.2020

Why does the Sun's surface keep changing? The help find out, the US National Science Foundation (NSF) has built the Daniel K. Inouye Solar Telescope in Hawaii, USA. The Inouye telescope...

APOD: 2026 June 6 Б Charon: Moon of Pluto
6.06.2026

A darkened and mysterious north polar region known to some as Mordor Macula caps this premier view of Charon, Pluto's largest moon. The high-resolution image was captured by the interplanetary space probe New Horizons near its closest approach to distant Pluto on July 14, 2015.

Voyager Views Titan s Haze
5.09.2002

Launched in 1977, 25 years ago today, the Voyager 1 spacecraft's historic tour of the outer Solar System took it past Saturn in late 1980. On November 12, 1980, Voyager 1 recorded this view looking across the edge of Titan, Saturn's largest moon, from a distance of about 22,000 kilometers.