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.
The Universe in Hot Gas
Where is most of the normal matter in the Universe? Recent observations from the Chandra X-ray Observatory confirm that it is in hot gas filaments strewn throughout the universe.…
Roque de los Muchachos Observatory
Above the clouds, atop an island off the coast of Africa, a group of cutting-edge telescopes inspects the universe. Pictured above are telescopes at Roque de los Muchachos…
Earth's North Magnetic Pole
A magnetic compass does not point toward the true North Pole of the Earth. Rather, it more closely points toward the North Magnetic Pole of the Earth. The North Magnetic Pole is…
Asteroid 2002 NY40
Asteroid 2002 NY40 will fly by planet Earth early in the morning August 18 Universal Time (late in the evening August 17 Eastern Daylight Time). Approaching to within about…
Rainbow Perseid
While meteors do show colors, the colors aren't always seen with the unaided eye. Still, high speed color film recorded this rainbow-like trail as a meteor streaked through the…
Meteors and Northern Lights
Skygazers report that the annual Perseid meteor shower went pretty much as predicted, producing a meteor every few minutes during the dark early morning hours of August 12 and 13.…
Giant Emission Nebula NGC 3603 in Infrared
NGC 3603 is the largest region of glowing gas in our Milky Way galaxy . Spanning over 20 light years across, the giant emission nebula (HII region) is home to a massive star…
Contemplating the Sky
Have you contemplated your sky recently? Last night was a good one for midnight meditators at many northerly locations as meteors from the Perseid meteor shower frequently…
The Colors and Mysteries of Centaurus A
Why is spiral galaxy Centaurus A in so much turmoil? The above composite image shows different clues to the unusual galaxy's past in different bands of light. In low energy radio…
A Perseid Meteor
The ongoing Perseid Meteor Shower should be at its strongest on August 12 and 13. The best time to watch will be between 2:00 AM and dawn on Monday morning ( so plan on setting…
Earth at Night
This is what the Earth looks like at night. Can you find your favorite country or city ? Surprisingly, city lights make this task quite possible. Human-made lights highlight…
Fireworks and Shooting Stars
Experimenting with a new telescope and camera, photographer Jim Steele captured this surreal but festive image of fireworks in the night sky above Ashland, Oregon. The date was…
Ancient Volcanos of Mars
Findings of ancient martian microbial fossils in meteorites and liquid water related features on Mars' surface are currently controversial issues. But one thing long established…
Gomez's Hamburger: A Proto-Planetary Nebula
What, in heaven, is that? Sometimes astronomers see things on the sky they don't immediately understand . In 1985 this happened to Arturo Gomez , and the object became known as…
Muon Wobble Possible Door to Supersymmetric Universe
How fast do fundamental particles wobble? A surprising answer to this seemingly inconsequential question is coming out of Brookhaven National Laboratory in New York , USA and may…
Rays from an Unexpected Aurora
This aurora was a bit of a surprise. For starters, last Friday morning, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to…
Spiral Galaxy NGC 2997 from VLT
NGC 2997 is a grand design spiral galaxy . Its small nucleus and sprawling spiral arms give it a type Sc designation. NGC 2997, pictured above , is speeding away from us at about…
The Galactic Center - A Radio Mystery
Tuning in to the center of our Milky Way galaxy, radio astronomers explore a complex, mysterious place. A premier high resolution view, this startlingly beautiful picture covers a…
Comet 57P Falls to Pieces
Comet 57P has fallen to pieces , at least 19 of them. Orbiting the Sun every 6 years or so this faint comet - also christened Comet 57P/du Toit-Neujmin-Delporte for its three 1941…
Sunspots and Solar Active Regions
July was a good month for sunspots ... really big sunspots. In fact, the full disk and inset pictures above show three large groups of spots, photographed only a few days ago on…
Henize 3-401: An Elongated Planetary Nebula
How do dying stars eject their outer layers? Stars that create elegant planetary nebulas like Henize 3-401, pictured above , are not unusual, causing speculation that, one day,…
A Star Cluster in Motion
Star clusters are a swarm of complex motions. The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting,…
A Setting Sun Trail
The Sun appears to move on the sky because the Earth rotates . The extreme brightness of the Sun , however, makes it difficult to capture a sun-trail -- the path the Sun traces on…
An Anomalous SETI Signal
No one knows for sure what caused this signal . There is a slight possibility that it just might originate from an extraterrestrial intelligence . The bright colors on the blue…
Viewing discoveries from 20 August 2002 through 28 July 2002.