Prometheus and the Rings of Saturn
17.12.2004

In Greek Mythology, Prometheus was known for stealing fire from the gods. Ironically, in a story for more modern times Prometheus may also become known for stealing, but this time for stealing icy particles from Saturn's rings.

Mercurys Horizon from MESSENGER
21.01.2008

What would it look like to fly past Mercury? Just such an adventure was experienced last week by the MESSENGER spacecraft during its first flyby of the strange moon-like world nearest the Sun. Pictured above is the limb of Mercury seen by MESSENGER upon approach, from about 1 1/2 Earth diameters away.

A Galaxy Collision in NGC 6745
30.09.2012

Galaxies don't normally look like this. NGC 6745 actually shows the results of two galaxies that have been colliding for only hundreds of millions of years. Just off the above digitally sharpened photograph to the lower right is the smaller galaxy, moving away.

Galaxy Evolution Tracking Animation
30.05.2016

How did the universe evolve from such a smooth beginning? To help understand, computational cosmologists and NASA produced the featured time-lapse animated video depicting a computer simulation of part of the universe. The 100-million light-year simulation starts about 20 million years after the Big Bang and runs until the present.

APOD: 2025 April 7 Б NGC 4414: A Flocculent Spiral Galaxy
7.04.2025

How much mass do flocculent spirals hide? The featured image of flocculent spiral galaxy NGC 4414 was taken with the Hubble Space Telescope to help answer this question. Flocculent spirals -- galaxies without well-defined spiral arms -- are a quite common form of galaxy, and NGC 4414 is one of the closest.

Barred Spiral Galaxy NGC 2903
21.03.2001

NGC 2903 is a spiral galaxy similar to our own Milky Way Galaxy. Similarities include its general size and a central bar. One striking difference, however, is the appearance of mysterious hot spots in NGC 2903's core. Upon

The Cliffs of Comet Churyumov Gerasimenko
22.12.2014

These high cliffs occur on the surface of a comet. They were discovered to be part of the dark nucleus of Comet ChuryumovGerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA which began orbiting the comet in early August. The ragged cliffs, as featured here, were imaged by Rosetta about two weeks ago.

APOD: 2025 April 21 Б Galaxy Lenses Galaxy from Webb
21.04.2025

Is this one galaxy or two? Although it looks like one, the answer is two. One path to this happening is when a small galaxy collides with a larger galaxy and ends up in the center. But in the featured image, something more rare is going on.

NGC4039: Starbirth and Galaxy Death
6.05.1997

Do star clusters form when galaxies collide? Quite possibly, according to Hubble Space Telescope observations of the "Antennae", two galaxies thought to be in the early stages of a collision.

Wind from a Black Hole
1.07.2006

Binary star system GRO J1655-40 consists of a relatively normal star about twice as massive as the Sun co-orbiting with a black hole of about seven solar masses. This striking artist's vision of the exotic binary system helps visualize matter drawn from the normal star by gravity and swirling toward the black hole.