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.
Jupiter: The Great Yellow Spot
Explanation : What happened to Jupiter's Great Red Spot ? Operating at a chilly 55 degrees Kelvin , the Galileo Spacecraft's Near Infrared Mapping Spectrometer (NIMS) recorded…
Jupiter: At The Belt-Zone Boundary
Explanation : Jupiter's thick atmosphere is striped by wind-driven cloud bands that remain fixed in latitude - dark colored bands are known as belts while light colored bands are…
COBE Hotspots:The Oldest Structures Known
Explanation : Above are two images of the microwave sky, north and south of our galaxy's equator , based on data from NASA's COsmic Background Explorer (COBE) satellite . After…
COBE Dipole: Speeding Through the Universe
Explanation : Our Earth is not at rest. The Earth moves around the Sun . The Sun orbits the center of the Milky Way Galaxy . The Milky Way Galaxy orbits in the Local Group . The…
Comet Hale-Bopp Enters the Evening Sky
Explanation : You no longer have to wake-up early to see Comet Hale-Bopp . From many northern locations, you can now go outside just after sunset and see Comet Hale-Bopp above the…
Hubble Floats Free
Explanation : Why put observatories in space? Most telescopes are on the ground. On the ground, you can deploy a heavier telescope and upgrade it more easily. The trouble is that…
In the Center of NGC 604
Explanation : Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33 , a large cloud of gas spawned dense internal knots which…
Solar Wind And Milky Way
Explanation: The Sun is bright, so bright that it overwhelms the light from other stars even for most satellite-borne telescopes. But LASCO, a coronograph onboard the space-based…
Pioneer 10: The First 6 Billion Miles
Explanation : Q: What was made by humans and is 6 billion miles away? A: Pioneer 10 - and yesterday was the 25th anniversary of its launch . More than 9 light hours distant,…
Hawaii
Explanation : Aloha! With the graceful arc of the Earth's limb in the background, the entire Hawaiian Island archipelago is visible in this stunning photo taken by the astronauts…
Galaxy Dwingeloo 1 Emerges
Explanation : Sometimes you can't see the forest for the trees. But if you look closely at the center of the above photograph , you will see a whole spiral galaxy behind the field…
Edge-On Spiral Galaxy NGC 891
Explanation : Is our Galaxy this thin? We believe so. The Milky Way , like NGC 891 pictured above , has the width of a typical spiral galaxy . Spirals have most of their bright…
Comet Hale-Bopp is That Bright
Explanation : What's that fuzzy star? It's not a star, it's Comet Hale-Bopp . Not only has Comet Hale-Bopp become easy to see in the morning sky , it has become hard not to see…
Sungrazer
Explanation : Arcing toward a fiery fate, this Sungrazer comet was recorded by the SOHO spacecraft's Large Angle Spectrometric COronagraph (LASCO) on Dec. 23rd, 1996. LASCO uses…
Star Wars in NGC 664
Explanation : Long ago in a galaxy far, far away, locked in their final desperate struggle against the force of gravity ... two stars exploded! Stellar explosions - Supernovae -…
The Trail of the Intruder
Explanation : In yesterday's episode our hero, the Cartwheel galaxy , had survived a chance cosmic collision with a small intruder galaxy - triggering an expanding ring of star…
Cartwheel of Fortune
Explanation : By chance, a collision of two galaxies has created a surprisingly recognizable shape on a cosmic scale - “The Cartwheel Galaxy” . The Cartwheel is part of a group of…
The Gamma Ray Sky
Explanation : What if you could “see” gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in…
New Eyes for the Hubble Space Telescope
Explanation : The Hubble Space Telescope 's second servicing mission has been completed. Every few years, the telescope is visited by a Space Shuttle to allow astronauts to switch…
Comet Hale-Bopp and the Dumbbell Nebula
Explanation : Comet Hale-Bopp is now slowly moving across the morning sky . During its trip to our inner Solar System , the comet passes in front of several notable objects. Here…
Mizar Binary Star
Explanation : Mizar (sounds like “My Czar”) is a binary star. In fact, most stars are binary stars . In a binary star system , each star of the pair follows an elliptical orbital…
A Big Cliff on Jupiter's Callisto
Explanation : Callisto 's surface is not without fault. In fact, an explorer crossing the surface of this large moon of Jupiter would need climbing equipment to pass this large,…
A Wind From The Sun
Explanation : A wind from the Sun blows through our Solar System . The behaviour of comet tails as they flapped and waved in this interplanetary breeze gave astronomers the first…
Betelgeuse, Betelgeuse, Betelgeuse
Explanation : Betelgeuse (sounds a lot like “beetle juice”), a red supergiant star about 600 light years distant, is seen in this Hubble Space Telescope image -- the first direct…
Viewing discoveries from 11 March 1997 through 16 February 1997.