The Holographic Principle
16.12.2007

Is this picture worth a thousand words? According to the Holographic Principle, the most information you can get from this image is about 3 x 10 65 bits for a normal sized computer monitor.

The Galactic Center Radio Arc
21.05.2002

What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane.

A Cerro Tololo Sky
9.11.2002

High atop a Chilean mountain lies one of the premier observatories of the southern sky: the Cerro Tololo Inter-American Observatory (CTIO). Pictured above is the dome surrounding one of the site's best known instruments, the 4-meter Blanco Telescope.

Pumpkin Moon
30.10.2004

Does this look familiar? Red and orange hues haunting the face of the Moon might remind you of the October 27th total lunar eclipse, but the picture is actually a montage of images from a similar lunar spectacle in May of 2003.

Shoreline Terrain on Saturns Titan
21.09.2005

What could have created this unusual terrain on Saturn's moon Titan? The robotic Cassini spacecraft now orbiting Saturn swooped once again, earlier this month, past the Solar System's most enigmatic moon and radar imaged a rich but unusual region that appears to be some sort of shoreline.

Mars Rocks, Sojourner Rolls
30.10.1999

This sharp color image featuring Mars rock Yogi and the rolling Sojourner robot shows off Yogi's two-toned surface. Yogi appears to be leaning into the prevailing winds causing some to suggest that its color contrast may be caused by the accumulation of rust colored dust on its windward face.

3D Full Moon
2.06.2007

Get out your red/blue glasses and check out this satisfying stereo anaglyph of the Full Moon. A corresponding stereo image pair, intended for cross-eyed viewing, is also available through this link. Regardless of your...

Eclipsed Moon and Mars over Mountains
7.08.2018

There is something unusual about this astronomically-oriented photograph. It's not obvious -- it was discovered only during post-processing. It is not the Moon, although capturing the Moon rising during a total lunar eclipse is quite an unusually interesting sight.

Apollo 14 Heads for Home
1.02.2020

When leaving lunar orbit in February 1971, the crew of Apollo 14 watched this Earthrise from their command module Kittyhawk. With Earth's sunlit crescent just peaking over the lunar horizon, the cratered terrain in the foreground is along the lunar farside.

APOD: 2025 July 6 Б The Spiral North Pole of Mars
6.07.2025

Why is there a spiral around the North Pole of Mars? Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere. This fresh layer is deposited on a water-ice layer that exists year round.