Ice at the Lunar South Pole
4.12.1996

Ice on the Moon? The prospecting Clementine spacecraft may well have discovered it. In 1994, Clementine spent 70 days in lunar orbit mapping the Moon's surface. Shown above is a dramatically detailed composite view centered on the Lunar South Pole - constructed from 1500 Clementine images.

The Horsehead Nebula
13.07.2003

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.

Apogee Moon, Perigee Moon
21.10.2004

Why don't these pieces fit? This third quarter Moon (left) and first quarter Moon were both photographed during the last lunar cycle or lunation with the same telescope and camera. But, simply combining the pictures into one sharp, full surface view would clearly be a problem.

Sun Block
18.08.1999

During a total solar eclipse, Earth's moon blocks the sun - almost exactly. While the sun is about 400 times wider than the moon, it is also about 400 times farther away and each appears to be half a degree or so in diameter.

Saturnian Moon and Rings
18.04.2005

When can a robot produce art? When it glides past the rings of Saturn, for one. As the robot spacecraft Cassini orbiting Saturn crossed outside the famous photogenic ring plane of the expansive planet, the rings were imaged from the outside, nearly edge on, and in the shadow of Saturn.

A Visit from Atlantis
28.06.2007

This remarkable image of the space shuttle orbiter Atlantis docked with the International Space Station (ISS) was taken at a range of 190 nautical miles. To record the fast moving pair, last week astronomers...

Moon Rays over Byurakan Observatory
26.09.2008

On September 7th, the first quarter Moon and passing clouds contributed to a dramatic night sky over the Byurakan Astrophysical Observatory. This panoramic view begins at the left looking toward the eastern horizon and the rising stars of the constellation Perseus.

Easter Island Eclipse
14.07.2010

Makemake, a god in Easter Island mythology, may have smiled for a moment as clouds parted long enough to reveal this glimpse of July 11's total solar eclipse to skygazers. In the foreground...

Mimas, Crater, and Mountain
11.01.2017

Mimas is an icy, crater-pocked moon of Saturn a mere 400 kilometers (250 miles) in diameter. Its largest crater Herschel is nearly 140 kilometers wide. About a third the diameter of Mimas itself, Herschel crater gives the small moon an ominous appearance, especially for scifi fans of the Death Star battlestation of Star Wars fame.

APOD: 2024 November 11 Б The Unusual Tails of Comet Tsuchinshan Atlas
11.11.2024

What created an unusual dark streak in Comet Tsuchinshan-Atlas's tail? Some images of the bright comet during mid-October not only caught its impressively long tail and its thin anti-tail, but a rather unexpected feature: a dark streak in the long tail.