Ptolemaeus, Alphonsus and Arzachel
9.02.2007

These three ancient, large impact craters lie on the north eastern shores of Mare Nubium, the lunar Sea of Clouds. Along the top of the stark mosaic (left to right) are the namesakes of Ptolemaeus, Alphonsus and Arzachel.

White Rock Fingers on Mars
15.02.2016

What caused this unusual light rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate a more mundane possibility: volcanic ash. Studying the exact color of the formation indicated the possible volcanic origin.

Messier 2
4.04.2019

After the Crab Nebula, M1, this giant star cluster is the second entry in 18th century astronomer Charles Messier's famous list of things with are not comets. M2 is one of the largest globular star clusters now known to roam the halo of our Milky Way galaxy.

The Little Dipper
14.05.2011

At 2nd magnitude, Polaris is far from the brightest star in the night sky. But it is the brightest star at the left of this well-composed, starry mosaic spanning about 23 degrees across the northern sky asterism dubbed the Little Dipper.

Milky Way Over the Bungle Bungles
11.09.2012

Which part of this picture do you find more interesting -- the land or the sky? Advocates for the land might cite the beauty of the ancient domes of the Bungle Bungle Range in Western Australia.

APOD: 2024 August 7 Б Milky Way Behind Three Merlons
7.08.2024

To some, they look like battlements, here protecting us against the center of the Milky Way. The Three Merlons, also called the Three Peaks of Lavaredo, stand tall today because they are made of dense dolomite rock which has better resisted erosion than surrounding softer rock.

The M7 Open Star Cluster in Scorpius
5.05.2002

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius.

Dark Craters on Ganymede
22.07.1998

Ganymede has craters within craters within craters. The old surface of the largest moon in the Solar System shows its age by the large amount of these impact features. The above picture released last...

The Drifts of Mars
8.11.2005

What would it be like to walk across Mars? The robot Opportunity rover is currently experiencing what it is like to roll across part of the red planet. It's not always easy -- the rover is being instructed to dodge the deeper drifts of dark sand.

The Past of Asteroid Eros
9.10.2001

How did large rocks come to be scattered on the surface of asteroid Eros? Eros stands out not only because of its proximity to Earth but also because it was visited recently by NASA's NEAR-Shoemaker spacecraft.