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.
Visitors' Galaxy Gallery
A tantalizing assortment of island universes is assembled here. From top left to bottom right are the lovely but distant galaxies M61 , NGC 4449 , NGC 4725 , NGC 5068 , NGC 5247 ,…
Horsehead Rides Again
Difficult to see in small telescopes, the Horsehead nebula was recently selected by internet voters as a target for the Hubble Space Telescope . Above (top) is Hubble's detailed…
Space Laser Creates Artificial Star
Some astronomers don't like stars. Bright star fluctuations can indicate how the Earth's atmosphere is changing, but many times no bright star exists in the direction where…
NGC 2264: Stars, Dust, and Gas
The nebula surrounding bright star S Mon is filled with dark dust and glowing gas. The strange shapes that haunt this star forming region originate from fine interstellar dust…
Space Shuttle Lifts Off for Space Station
Last Thursday, Space Shuttle Endeavor lifted off on course for the latest round of building the International Space Station (ISS) in orbit around Earth. One of the highlights of…
Globular Cluster 47 Tucanae
Stars come in bunches. Of the over 200 globular star clusters that orbit the center of our Milky Way Galaxy , 47 Tucanae is the second brightest globular cluster (behind Omega…
Apollo 12: Stereo View Near Surveyor Crater
This weekend's stereo picture finds Apollo 12 astronaut Pete Conrad standing on the lunar surface near the southern rim of Surveyor Crater in November of 1969. With red/blue…
Io: Moon Over Jupiter
How big is the Jovian moon Io ? The most volcanic body in the Solar System, Io (usually pronounced “EYE-oh”) is 3,600 kilometers in diameter, about the size of planet Earth's…
Sunspot Stack
Welcome to multiwavelength astronomy ! From top to bottom, these stacked panels show the largest sunspot group in a decade in visible, extreme ultraviolet, and x-ray light. All…
A Higher Dimensional Universe?
Does our universe have higher but unusual spatial dimensions ? This idea has been gaining popularity to help explain why vastly separated parts of our universe appear so similar ,…
Colorful Water Clouds Over Mars
One place where water can be found on Mars is in clouds . In the above picture colorful water clouds are visible just after sunrise in and around a maze of canyons known as Noctis…
The Hydra Cluster of Galaxies
The Hydra Cluster of Galaxies contains well over 100 bright galaxies - but perhaps fewer galaxies than might be expected from its mass. Clusters of galaxies are the largest…
Diffraction Spikes: When Stars Look Like Crosses
Unusual appendages around bright stars are commonplace, but never seem to be mentioned. What are they? First, a telescope brings starlight falling over a large area to a small…
Man Enters Space
Forty years ago, on April 12, 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human in space. His remotely controlled Vostok 1 spacecraft lofted him to an…
GRB010222: Gamma-Ray Burst, X-Ray Afterglow
A fading afterglow from one of the most powerful explosions in the universe is centered in this false color image from the spacebased Chandra X-ray Observatory . The cosmic…
STS-1: First Shuttle Launch
On April 12, 1981, twenty years ago today, the space shuttle orbiter Columbia became the first shuttle to orbit the Earth. In this gorgeous time exposure , flood lights play on…
Large Sunspot Group AR 9393
The largest sunspot group of the past ten years crossed the surface of the Sun late last month and early this month. The group was designated Active Region 9393 as it was the…
M51: The Whirlpool Galaxy in Dust and Stars
The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51 , also known as NGC 5194, is one of the…
Mars Odyssey Lifts Off for Mars
Next stop: Mars. On Saturday the 2001 Mars Odyssey spacecraft lifted off from Cape Canaveral , Florida on a path to enter orbit around Mars in late October. Pictured above , a…
The Big Corona
Most photographs don't adequately portray the magnificence of the Sun 's corona. Seeing the corona first-hand during a total solar eclipse is best. The human eye can adapt to see…
Stereo Sun
This week's stereo offering features the now famous Active Region 9393, the largest sunspot group in the last 10 years. Viewed with red/blue glasses , the stereo pair of images…
Aurora Over New Zealand
Last weekend skygazers at middle and high latitudes around the globe were treated to expansive auroral displays as a magnetic storm raged around planet Earth . The storm was…
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…
Distant Supernova, Dark Energy
A pinpoint of light from a star that exploded over 10 billion light-years away is centered in the panel at the lower right, a cosmic snapshot of the most distant supernova . The…
Viewing discoveries from 27 April 2001 through 4 April 2001.