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.
Saturn: Shadows of a Seasonal Sundial
Saturn's rings form one of the larger sundials known. This sundial , however, determines only the season of Saturn, not the time of day. In 2009, during Saturn's last equinox ,…
NGC 7635: The Bubble Nebula
It's the bubble versus the cloud. NGC 7635, the Bubble Nebula , is being pushed out by the stellar wind of massive central star BD+602522 . Next door, though, lives a giant…
A Strange Sunrise Over Argentina
Why would a rising Sun look so strange? No one is yet sure. What is clear is that the above unusual sunrise was captured last month from Buenos Aires , Argentina . The body of…
Nobels for a Strange Universe
Thirteen 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…
MESSENGER's First Day
One solar day on a planet is the length of time from noon to noon. A solar day lasts 24 hours on planet Earth. On Mercury a solar day is about 176 Earth days long. And during its…
The Comet Hartley 2 Cruise
Early last November, small but active Comet Hartley 2 (103/P Hartley) became the fifth comet imaged close-up by a spacecraft from planet Earth . Still cruising through the solar…
M82: Starburst Galaxy with a Superwind
Also known as the Cigar Galaxy for its elongated visual appearance, M82 is a starburst galaxy with a superwind. In fact , through ensuing supernova explosions and powerful winds…
Comet and CME on the Sun
Did a sun-diving comet just cause a solar explosion? Probably not. This past weekend a comet dove toward the Sun and was followed very quickly by a Coronal Mass Ejection (CMEs)…
QR Codes: Not for Human Eyes
This communication was not meant for human eyes. It was not even meant for aliens eyes . It's an attempt to communicate directly with your smartphone . Cameras on many smartphones…
Dark Matter Movie from the Bolshoi Simulation
What if you could fly through the universe and see dark matter? While the technology for taking such a flight remains under development, the technology for visualizing such a…
Tunguska: The Largest Recent Impact Event
Yes, but can your meteor do this? The most powerful natural explosion in recent Earth history occurred on 1908 June 30 when a meteor exploded above the Tunguska River in Siberia ,…
Asteroids Near Earth
Though the sizes are not to scale, the Sun and planets of the inner solar system are shown in this illustration, where each red dot represents an asteroid. New results from…
Cloudy Night of the Northern Lights
On September 26 , a large solar coronal mass ejection smacked into planet Earth's magnetosphere producing a severe geomagnetic storm and wide spread auroras. Captured here near…
Cocoon Nebula Wide Field
In this crowded starfield spanning some 3 degrees within the high flying constellation Cygnus , the eye is drawn to the Cocoon Nebula. A compact star forming region, the cosmic…
Violent Sunspot Group AR 1302 Unleashes a Flare
One of the most active sunspot groups in years is currently crossing the Sun. AR 1302 first came around the Sun's edge last week and is so large it can be seen without a…
Flying Over Planet Earth
Have you ever dreamed of flying high above the Earth? Astronauts visiting the International Space Station do this every day, circling our restless planet twice every three hours.…
Dry Ice Pits on Mars
Part of Mars is defrosting. Around the South Pole of Mars, toward the end of every Martian summer, the warm weather causes a section of the vast carbon-dioxide ice cap to…
A Large Tsunami Shock Wave on the Sun
Tsunamis this large don't happen on Earth. During 2006, a large solar flare from an Earth-sized sunspot produced a tsunami -type shock wave that was spectacular even for the Sun.…
Mangaia's Milky Way
From Sagittarius to Carina , the Milky Way Galaxy shines in this dark night sky above planet Earth's lush island paradise of Mangaia . Familiar to denizens of the southern…
September's Aurora
September's equinox arrives today at 0905 UT. As the Sun crosses the celestial equator heading south, spring begins in the southern hemisphere and autumn in the north. And though…
Arp 272
Linking spiral arms, two large colliding galaxies are featured in this remarkable cosmic portrait constructed using image data from the Hubble Legacy Archive . Recorded in…
Pleiades Deep Field
Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it like this: all dusty. Perhaps the most famous star cluster on the sky, the bright…
Kepler-16b: A Planet with Two Suns
If you stay up long enough, you can watch both suns set. Such might be a common adage from beings floating in the atmosphere of Kepler 16b, a planet recently discovered by the…
The South Pole of Asteroid Vesta
What created the circular structure around the south pole of asteroid Vesta? Pictured above , the bottom of the second largest object in the asteroid belt was recently imaged for…
Viewing discoveries from 12 October 2011 through 19 September 2011.