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.
Three Views of Jupiter's Io
Explanation : The Galileo spacecraft orbiting Jupiter continues to return impressive results. The Galileo team has just released three more photographs of Jupiter 's volcanic moon…
Orion's Horsehead Nebula
Explanation : The Horsehead Nebula is arguably the most famous nebula on the sky. It is visible as the black indentation to the red emission nebula seen just to the right of…
BATSE's Biggest Gamma Ray Burst (Yet)
Explanation : Something big exploded but astronomers have no idea what. On September 24 th , the Burst and Transient Source Experiment (BATSE) onboard the orbiting Compton Gamma…
Exploring The Universe With IUE (1978-1996)
Explanation : How do planets, stars, and galaxies form? How do they evolve? The International Ultraviolet Explorer (IUE) satellite was launched in 1978 and operated by NASA / ESA…
The X-Ray Moon
Explanation : This X-Ray image of the Moon was made by the orbiting Roentgen Observatory Satellite ( ROSAT ) in 1990. It shows three distinct regions: a bright X-ray sky, a bright…
A Soyuz at Mir
Explanation : Pictured above is a three person Russian Soyuz capsule with wing-like solar panels extended, joined to the Mir space station . In Russian soyuz means “union” and…
Welcome Home Shannon Lucid
Explanation : Today is Shannon Lucid's first day on Planet Earth in six months. Her stay aboard Russia's Mir Space Station was of record length - the longest stay of any American…
Tonight: A Total Lunar Eclipse
Explanation : Tonight brings the last total lunar eclipse visible from North America until the year 2000 - with the Moon becoming completely immersed in Earth's shadow. The above…
Bright Stars and Dark Clouds
Explanation : Did you ever feel like a black cloud was following you around? Well don't feel bad - this even happened to the bright young stars of the open cluster NGC 6520. On…
Beneath Venus' Clouds
Explanation : If the thick clouds covering Venus were removed, how would the surface appear? Using an imaging radar technique, the Magellan spacecraft was able to lift the veil…
Venus: Earth's Cloudy Twin
If Venus weren't so cloudy it would be more similar to Earth. This picture by the Galileo spacecraft shows just how cloudy Venus is. Venus is very similar to Earth in size and…
The Equal Night
Today the Sun crosses the celestial equator heading south -- marking the Autumnal Equinox, the first day of Autumn. Equinox means equal night and with the Sun on the celestial…
The Ecliptic Plane
The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over…
Hurricane Fran's Approach
Two weeks ago Hurricane Fran, pictured above , struck the east coast of the United States . Hurricanes are huge swirling storms with cloud systems typically larger than a state.…
The Moon and All the Crashes
A clear blue summer sky finally grows dark and the new telescope, hastily set up in the backyard, generates excitment and anticipation. “I bought it for the kids ...”, Dad assures…
Stars in the Infrared Sky
What if you could see infrared light ? Because this light is less absorbed by dust than visible light, you could peer into the center of our Milky Way Galaxy. The stars there are…
Comet Hale-Bopp Fades
Comet Hale-Bopp has faded in the past few weeks. For Hale-Bopp , promised as the Great Comet of 1997, this was a bit of a disappointment -- but not entirely unexpected. Comet…
The Sun Erupts
The Sun is a seething ball of extremely hot gas. Above, the Sun was captured by Skylab in 1973 throwing off one the largest eruptive prominences in recorded history. The Sun has…
Tycho Brahe Measures the Sky
Tycho Brahe was the most meticulous astronomical observer of his time. Brahe, who lived between 1546 and 1601, set out to solve the day's most pressing astronomical problem: to…
Aristarchus' Unbelievable Discoveries
Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified…
Southwest Mercury
The planet Mercury resembles a moon. Mercury 's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter 's moon Ganymede and…
Mercury: A Cratered Inferno
Mercury's surface looks similar to our Moon's. Each is heavily cratered and made of rock. Mercury 's diameter is about 4800 km, while the Moon 's is slightly less at about 3500 km…
In the Center of Spiral M77
What is happening in the center of nearby spiral galaxy M77? To find out, astronomers used the Hubble Space Telescope to peer deep into the dusty chaos of this active galactic…
M77: Spiral with a Strange Glow
Why is M77 surrounded by an ultraviolet glow? M77 , also called NGC 1068, appears at first sight to be a relatively normal barred spiral galaxy . But when photographed in the…
Viewing discoveries from 3 October 1996 through 10 September 1996.