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 Space Shuttle Docked with Mir
Before there was the International Space Station , the reigning orbiting spaceport was Russia's Mir. Pictured above in 1995, the United States Space Shuttle Atlantis docked with…
Io's Surface: Under Construction
Like the downtown area of your favorite city, the roads you drive to work on, and any self-respecting web site ... Io's surface is constantly under construction . This moon of…
At the Center of the Milky Way
At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually…
Centaurus A: Young Blue Star Stream
Almost lost in this cosmic jumble of stars, gas and dust is a faint but definite blue arc -- a stream of young stars whose formation was probably triggered as a small dwarf galaxy…
Oklo: Ancient African Nuclear Reactors
The remnants of nuclear reactors nearly two billion years old were found in the 1970s in Africa. These reactors are thought to have occurred naturally. No natural reactors exist…
Aurora's Ring
Gusting solar winds and blasts of charged particles from the Sun made the early days of October rewarding ones for those anticipating auroras . While out enjoying the stormy space…
IC 5146: The Cocoon Nebula
How did this nebula get created? The Cocoon Nebula , cataloged as IC 5146, is a strikingly beautiful nebula located about 4,000 light years away toward the constellation of Cygnus…
CG4: A Ruptured Cometary Globule
The odd looking “creature” to the right of center in the above photo is a gas cloud known as a cometary globule . This globule, however, has ruptured. Cometary globules are…
Chandra Deep Field
Officially the Chandra Deep Field - South , this picture represents the deepest ever x-ray image of the Universe. One million seconds of accumulated exposure time with the…
Fomalhaut Dust Disk Indicates Planets
One of the brightest stars on the sky likely has planets. Fomalhaut , actually the 17th brightest star in the night sky, is a mere 22 light-years away but only a fraction of the…
Dusty Environs of Eta Carinae
Eta Car is a massive star, but it's not as bright as it used to be. Now only easily visible in binoculars or a small telescope, Eta Carinae has a history of spectacular flaring…
Quaoar: Large Asteroid in the Outer Solar System
Asteroids almost as large as planets are still being discovered in our own Solar System . Recently an asteroid more than half the size of Pluto was found orbiting at a distance…
The X-Ray Jets of XTE J1550
The motion of ultra-fast jets shooting out from a candidate black hole star system have now been documented by observations from the orbiting Chandra X-ray Observatory . In 1998,…
The Galaxy and the Quasar
Is the galaxy in the center connected to the quasar on the upper right? Disagreements about systems like this have raged for decades and have been used to challenge the…
The Lagoon Nebula in Three Colors
The bright Lagoon Nebula is home to a diverse array of astronomical objects. Particularly interesting sources include a bright open cluster of stars and several energetic…
X-Ray Cygnus A
Amazingly detailed, this false-color x-ray image is centered on the galaxy Cygnus A. Recorded by the orbiting Chandra Observatory , Cygnus A is seen here as a spectacular high…
Facing NGC 6946
From our vantage point in the Milky Way Galaxy , we see NGC 6946 face on. The big beautiful spiral galaxy is located just 10 million light-years away, behind a veil of foreground…
V838 Mon: Mystery Star
A leading candidate for the most mysterious star found in recent times is variable star V838 Monocerotis . At a distance of about 8,000 light-years, V838 Mon was discovered to be…
Star Clouds Toward the Southern Crown
The flowing trails of dust toward Corona Australis , the constellation of the Southern Crown , are visible here not because they glow , but because they absorb and reflect . The…
Rectangular Ridges on Mars
What could cause rectangular ridges on Mars? As data flows in from the two spacecraft currently orbiting Mars , surface structures are seen that are not immediately understood.…
D. rad Bacteria: Candidate Astronauts
These bacteria could survive on another planet. In an Earth lab, Deinococcus radiodurans (D. rad) survive extreme levels of radiation , extreme temperatures, dehydration , and…
Venus: Just Passing By
Venus, the second closest planet to the Sun , is a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus…
X-Ray Rainbows
A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors . In order of increasing energy, the well known spectrum of colors in a rainbow runs…
Accretion Disk Simulation
Don't be fooled by the familiar symmetry. The graceful spiral structure seen in this computer visualization does not portray winding spiral arms in a distant galaxy of stars .…
Viewing discoveries from 20 October 2002 through 27 September 2002.