Browse NASA Astronomy Picture of the Day archive by date and media: Archive Discoveries
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The M81 Galaxy Group Through the Integrated Flux Nebula
Large galaxies and faint nebulae highlight this deep image of the M81 Group of galaxies. First and foremost in the wide-angle 12-hour exposure is the grand design spiral galaxy…

Retrograde Mars
Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About…

Stars and Mars
Wandering through the evening sky , on May 4th planet Mars stood in line with Castor and Pollux, the two bright stars of the constellation Gemini . In this time exposure of the…

Moon Meets Mercury
On Tuesday, May 6, while standing on planet Earth and sweeping your binoculars along the western horizon just after sunset , you might have encountered this arresting skyscape.…

The Dark Tower in Scorpius
In silhouette against a crowded star field toward the constellation Scorpius , this dusty cosmic cloud evokes for some the image of an ominous dark tower . In fact, clumps of dust…

The Gegenschein Over Chile
Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for “counter glow”) can be seen 180…

Galaxies Collide in NGC 3256
Galaxies don't normally look like this. NGC 3256 actually shows a current picture of two galaxies that are slowly colliding . Quite possibly, in hundreds of millions of years,…

A Persistent Electrical Storm on Saturn
How do large storms evolve on Saturn? On Earth, a hurricane can persist for weeks, while the Great Red Spot on Jupiter has been in existence for over 150 years. On Saturn , a…

An Antarctic Total Solar Eclipse
The Sun, the Moon, Antarctica, and two photographers all lined up in 2003 Antarctica during an unusual total eclipse of the Sun. Even given the extreme location, a group of…

Alborz Mountain Milky Way
Snow-capped stratovolcano Mt. Damavand climbs to 5,670 meters (18,598 feet) near the left edge in this panoramic view of the world at night . In the sky to the left of Damavand's…

Shaping NGC 6188
Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large…

The Giants of Omega Centauri
Globular star cluster Omega Centauri is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars, Omega Cen is the largest of 200 or so…

Arp 272
Linking spiral arms, two large colliding galaxies are featured in this Hubble Space Telescope view, part of a series of cosmic snapshots released to celebrate the Hubble's 18th…
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Airplane Flight Patterns over the USA
What are these Earthlings going? Millions of people move about planet Earth by airplane every day. Hundreds of thousands of airplane flights take place over the US every day. A…

Star Forming Region NGC 3582
What's happening in the NGC 3582 nebula? Bright stars and interesting molecules are forming. The complex nebula resides in the star forming region called RCW 57. Visible in this…

The Galactic Center Radio Arc
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…

The Tarantula Zone
The Tarantula Nebula is more than 1,000 light-years in diameter -- a giant star forming region within our neighboring galaxy the Large Magellanic Cloud (LMC). That cosmic arachnid…

M86 in the Virgo Cluster
Bright lenticular galaxy M86 is near center of this cosmic view, at the heart of the Virgo Galaxy Cluster . Other bright galaxies in the neighborhood include M84 at the upper…

Cygnus Without Stars
The sky is full of hydrogen, though it can take a sensitive camera and telescope to see it. For example, this twelve-degree-wide view of the northern part of the constellation…

Above the Clouds
From the windswept peak of Mauna Kea , on the Big Island of Hawaii, your view of the world at night could look like this. At an altitude of about 13,500 feet, the mountain top is…

The Fox Fur Nebula from CFHT
This interstellar beast is formed of cosmic dust and gas interacting with the energetic light and winds from hot young stars. The shape, visual texture, and color, combine to give…

Bacteriophages: The Most Common Life-Like Form on Earth
There are more bacteriophages on Earth than any other life-like form. These small viruses are not clearly a form of life , since when not attached to bacteria they are completely…

Spiral Galaxies in Collision
Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of…

Running Messier's Marathon
Gripped by an astronomical spring fever, many northern hemisphere stargazers embark on a Messier Marathon . Completing the marathon requires viewing all 110 objects in 18th…
Viewing discoveries from 12 May 2008 through 19 April 2008.