Browse NASA Astronomy Picture of the Day archive by date and media: Archive Discoveries
Browse the NASA APOD archive without needing the exact date first. Filter by media type and keep moving deeper into older images and videos.
Upgrading the International Space Station
The International Space Station (ISS) will be the largest human-made object ever to orbit the Earth . The station is so large that it could not be launched all at once -- it is…
Rumors of a Strange Universe
Eight years ago results were first presented indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of…
The Analemma and the Temple of Olympian Zeus
An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day throughout planet Earth's year. Above, 47 separate exposures (plus one…
The View from Stereo Ahead
On December 22nd, at 0022 Universal Time the Sun reached its southernmost point in Earth's sky marking the final season change for the year 2006. In celebration of the Solstice ,…
Minotaur Dawn
Last Saturday , some colorful dawn skies along the US east coast featured the Moon and a Minotaur rocket climbing into low Earth orbit. The 7AM launch of the four stage Air Force…
Star Forming Region NGC 6357
For reasons unknown, NGC 6357 is forming some of the most massive stars ever discovered. Near the more obvious Cat's Paw nebula, NGC 6357 houses the open star cluster Pismis 24 ,…
Massive Stars in Open Cluster Pismis 24
How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of…
Aurora Over Iowa
Last Thursday evening, stars were not the only lights in Iowa skies. Spectacular northern lights also shone from the heavens, extending across the midwestern USA and other…
A Force from Empty Space: The Casimir Effect
This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to…
A Path To Orion
Last Saturday, the Space Shuttle Discovery lit up the night as it climbed into orbit above planet Earth . From Oak Hill, Florida, USA - about 30 miles north of the Kennedy Space…
NGC 1055 and M77
Large spiral galaxy NGC 1055 (top left) joins spiral M77 in this lovely cosmic view toward the constellation Cetus . The narrowed, dusty appearance of edge-on spiral NGC 1055…
Mountains of Titan
Peering through the thick, hazy atmosphere of Saturn's largest moon, an infrared camera onboard the Cassini spacecraft recorded this view of the tallest mountains ever seen on…
A Large Tsunami Shock Wave on the Sun
Tsunamis this large don't happen on Earth. One week ago, a large solar flare from an Earth-sized sunspot produced a tsunami -type shock wave that was spectacular even for the Sun.…
Light Deposits Indicate Water Flowing on Mars
What's creating light-toned deposits on Mars? Quite possibly -- water! Images of the same parts of mid-latitude Mars taken over the years but released only last week have shown…
IC 2118: The Witch Head Nebula
Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is…
Apollo 17 Panorama: Astronaut Running
What would it be like to explore the surface of another world? In 1972 during the Apollo 17 mission, astronaut Harrison Schmitt found out first hand. In this case, the world was…
Three Planets in Dawn Skies
Three children of the Sun rise in the east in this peaceful dawn skyview recorded December 7th near Bolu, Turkey. Inner planet Mercury , fresh from its second transit of the 21st…
NGC 2174: Emission Nebula in Orion
A lesser known sight in the nebula-rich constellation Orion, NGC 2174 can be found with binoculars near the head of the celestial hunter . About 6,400 light-years distant, the…
The Outskirts of M77
Face-on spiral galaxy M77 lies a mere 60 million light-years away toward the aquatic constellation Cetus . Also known as NGC 1068, its very bright core is well studied by…
Spirit Rover on Mars Imaged from Orbit
If you have the right equipment, you can see the Spirit rover currently rolling across Mars. The right equipment, however, is currently limited to the High Resolution Imaging…
The Antikythera Mechanism
What is it? It was found at the bottom of the sea aboard an ancient Greek ship. Its seeming complexity has prompted decades of study, although many of its functions remained…
Movie: The Active Sun
Plumes of hot gas shoot across the surface on even an average day on the Sun. Such volatile activity was captured in dramatic detail recently by the new Hinode satellite launched…
Phobos: Doomed Moon of Mars
This moon is doomed. Mars , the red planet named for the Roman god of war , has two tiny moons, Phobos and Deimos , whose names are derived from the Greek for Fear and Panic.…
Star Trails at 19,000 Feet
In myth, Atlas holds up the heavens, but in this stunning view a mountain appears to serve as the southern night sky pivots around a snowy peak. Recorded during a climbing…
Viewing discoveries from 25 December 2006 through 2 December 2006.