Browse NASA Astronomy Picture of the Day archive by date and media: Archive Discoveries
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Saturn: Dirty Rings and a Clean Moon
Eating surface ice from Enceladus might be healthier than eating ice from Saturn's rings -- it certainly appears cleaner. From their apparent densities and reflectance properties,…
A Milky Way Band
Most bright stars in our Milky Way Galaxy reside in a disk. Since our Sun also resides in this disk, these stars appear to us as a diffuse band that circles the sky. The above…
First U.S. Spacewalk
In 1965, forty years ago on June 3rd, astronaut Edward White made the first U.S. spacewalk . Tethered to his Gemini IV capsule, White is pictured above holding a compressed gas…
M27: The Dumbbell Nebula
The first hint of what will become of our Sun was discovered inadvertently in 1764 . At that time, Charles Messier was compiling a list of diffuse objects not to be confused with…
Sculpting the South Pillar
Eta Carinae , one of the most massive and unstable stars in the Milky Way Galaxy, has a profound effect on its environment. Found in the the South Pillar region of the Carina…
White Dwarf Star Spiral
About 1,600 light-years away, in a binary star system fondly known as J0806 , two dense white dwarf stars orbit each other once every 321 seconds . Interpreting x-ray data from…
The Trifid Nebula from CFHT
Unspeakable beauty and unimaginable bedlam can be found together in the Trifid Nebula . Also known as M20, this photogenic nebula is visible with good binoculars towards the…
A Great White Spot on Rhea
What caused this great white spot on the surface of Saturn's moon Rhea? The spot was first noticed last year by the robot Cassini spacecraft now orbiting Saturn . Cassini's flyby…
The Sagittarius Dwarf Tidal Stream
Is our Milky Way Galaxy out to lunch? Recent wide field images and analyses now indicate that our home galaxy is actually still in the process of devouring one of its closer…
Himalayan Horizon From Space
This stunning aerial view shows the rugged snow covered peaks of a Himalayan mountain range in Nepal. The seventh-highest peak on the planet , Dhaulagiri, is the high point on the…
Titan's Odd Spot
Titan's odd spot could be a cloud, but if so, it's a persistent one. Peering into the thick, hazy atmosphere of Saturn's largest moon , cameras on board the Cassini spacecraft…
A Beautiful Trifid
The beautiful Trifid Nebula (aka M20) , a photogenic study in cosmic contrasts, lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming…
Particle Sizes in Saturn's Rings
What size particles compose Saturn's rings? To help find out, the robot Cassini spacecraft now orbiting Saturn broadcast radio waves of three different wavelengths right through…
Swirls and Stars in IC 4678
Swirls of gas and dust enrich this little observed starfield toward the constellation of Sagittarius . Just to the side of the more often photographed Lagoon Nebula ( M8 ) and the…
A Wave Maker Moon in Saturn's Rings
What causes small waves in Saturn's rings? Observations of rings bordering the Keeler gap in Saturn's rings showed unusual waves. Such waves were first noticed last July and are…
The Dust and Ion Tails of Comet Hale-Bopp
In 1997, Comet Hale-Bopp 's intrinsic brightness exceeded any comet since 1811 . Since it peaked on the other side of the Earth's orbit, however, the comet appeared only brighter…
Snake in the Dark
Dark nebulae snake across a gorgeous expanse of stars in this wide-field view toward the pronounceable constellation Ophiuchus and the center of our Milky Way Galaxy. In fact, the…
Aurora Iowa
Early last Sunday morning stars were not the only lights in Iowa skies. The northern lights also shone from the heavens, extending across the midwestern USA and other locations…
X-Ray Stars in the Orion Nebula
When our middle-aged Sun was just a few million years old it was thousands of times brighter in x-rays . In fact, it was likely similar to some of the stars found in this…
Three Kilometers Above Titan
What did the Huygens probe see as it descended toward Saturn's Moon Titan? In January the robot Cassini spacecraft now orbiting Saturn released a probe through the dense cloud…
A Panorama of Mars from Larry's Lookout
Scroll right to see a breathtaking panorama of Mars from Larry's Lookout. The lookout occurs near the peak of Husband Hill in the Columbia Hills . The summit of Husband Hill is…
Deep Impact Spacecraft Hurtles Toward Comet
What happens when you crash into a comet? That was a question considered by astronomers when they designed the Deep Impact mission , launched in January. This coming July 4, the…
On the Origin of Gold
Where did the gold in your jewelry originate? No one is completely sure . The relative average abundance in our Solar System appears higher than can be made in the early universe…
NGC 3370: A Sharper View
Similar in size and grand design to our own Milky Way , spiral galaxy NGC 3370 lies about 100 million light-years away toward the constellation Leo. Recorded here in exquisite…
Viewing discoveries from 6 June 2005 through 14 May 2005.