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.
M81 in True Color
Here's what a spiral galaxy REALLY looks like. Yesterday, M81 was shown in two colors only, but here we see M81 at its most colorful . In the above picture , note how blue the…
M81: A Bulging Spiral Galaxy
Few stars are still forming in the old giant spiral galaxy M81. The blue regions in this picture - representing ultraviolet light - highlight regions of bright young stars and…
Ancient Cratered Plains on Ganymede
The largest moon in the Solar System shows regions that are ancient and battered. The high density of craters demonstrate that patches of Ganymede are indeed billions of years…
Ganymede: A Really Groovy Moon
Ganymede's surface is a wrinkled mess. As large ice-sheets shift on the moon's surface , parts of the surface buckle causing high ridges, deep furrows, and parallel grooves. This…
Galileo Photographs Ganymede
Ganymede's surface is slowly being pulled apart. This photo of Ganymede was released earlier today by the Galileo team at NASA. The Galileo Spacecraft arrived at Jupiter in…
M74: A Grand Design Spiral Galaxy
M74 is about the same size as our own Milky Way Galaxy. Like our Milky Way , M74 is classified a spiral galaxy. M74's sweeping lanes of stars and dust combined with its small…
M33: The Triangulum Galaxy
The spiral galaxy M33 is a mid-sized member of our Local Group of galaxies . M33 is also called the Triangulum Galaxy for the constellation in which it resides. About four times…
Isaac Newton Explains the Solar System
Sir Isaac Newton changed the world. Born in 1643, Newton was only an above-average student. But he went home from Cambridge one summer in 1665, thought a lot about the physical…
Edmond Halley's Greatest Discoveries
Sir Edmond Halley was quite a discoverer. Born in 1656, he computed in 1705 that a bright comet was periodic and would make another appearance in 1758. The comet appeared as…
The Mysterious Rings of Supernova 1987a
What's causing those odd rings in supernova 1987a? In 1987, the brightest supernova in recent history occurred in the Large Magellanic Clouds . At the center of the picture is an…
The Cat's Eye Nebula (Revisited)
Three thousand light years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals “The Cat's Eye Nebula” to be one of the most…
Superbubbles in the LMC
Why is there a hole in the center of this nebula? A leading explanation is that it is caused by the stellar winds from the stars that live there. Stars - including the Sun - expel…
NASA's Latest Rockets: X-33
What will NASA rockets look like in the future? Today's announcement gave one indication. Today Vice- President Al Gore announced that the Lockheed Martin Corporation will work…
Worlds of a Distant Sun: 47 Ursae Majoris b
Within the last few years, observational astronomy has given humanity evidence of the existence of worlds beyond the solar system. Indeed, solar-type stars are now inferred to…
Greetings from the Pioneers
Launched in the early 1970s Pioneer 10 and 11 were appropriately named - becoming the first spacecraft to travel through the asteroid belt, first to fly by Jupiter and Saturn ,…
The Voyagers' Message in a Bottle
Launched in the summer of 1977 , NASA's Voyager 1 and 2 spacecraft are now over 4.5 billion miles from the Sun. Still operational , the Voyagers are being tracked and commanded…
A Distant Galaxy in the Deep Field
Researchers believe that the faint reddish smudge indicated by the arrow in the image above is a candidate for the most distant known galaxy which may have existed only a few…
Voyager's Preview of Galileo at Ganymede
NASA's robot spacecraft Galileo began its long voyage to Jupiter in October of 1989. In December of last year it arrived in the Jovian system, beginning its unprecedented,…
Happy Birthday Charles Messier: M1
French astronomer Charles Messier was born on June 26, 1730 . Inspired by childhood sightings of comets and a solar eclipse visible from his home town of Badonvillier, he became…
A Star Forming Region in the LMC
Stars sometimes form in colorful ways. Pictured above is a small region in the nearby LMC galaxy where stars are forming. After a star is born , it may do several things to…
A View from Venus: Rift Valley
Color information from the Soviet Venera landers and radar data from the Magellan spacecraft were used to construct this striking perspective view of the Venusian landscape . (In…
Tycho's Supernova Remnant in X-ray
How often do stars explode? By looking at external galaxies, astronomers can guess that these events, known as a supernovae , should occur about once every 30 years in a typical…
North to the Moon's Pole
This image is from the voyage of the intrepid Galileo spacecraft as it passed above the Moon's north pole on its long journey to Jupiter . It was made over 60 years after Admiral…
A Very Large Array of Radio Telescopes
Pictured above is one of the world's premiere radio astronomical observatories: The Very Large Array (VLA). Each antenna dish is as big as a house (25 meters across) and mounted…
Viewing discoveries from 14 July 1996 through 21 June 1996.