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.
Hyakutake: Stars Through A Comet's Tail
Comets are cosmic icebergs . They follow very elongated orbits which carry them from the frozen, remote outer reaches of the Solar System to close encounters with the Sun . Heated…
X-Ray Triple Jet
Recorded on July 7 , this animation using X-ray images of the Sun shows an amazing event - three nearly simultaneous jets connected with solar active regions. The two frames were…
Ghost Galaxy NGC 2915
How do you find a nearly invisible galaxy? Pictured above is the blue compact dwarf (BCD) galaxy NGC 2915 . In visible light, shown above in yellow, this galaxy appears to be a…
At Work on Mars
To learn about the history of Mars , just ask the rocks. Last year, that's exactly what the robot rover Sojourner did. Sojouner can be seen, above, analyzing a rock nicknamed Moe…
GRB 980703: A Reassuring Redshift
In the old days, just over a year ago, astronomers had little idea of the true distance to gamma-ray bursts . Did these enigmatic explosions occur in our outer Galaxy , or in the…
Asteroid Gaspra's Best Face
Asteroid 951 Gaspra is a huge rock tumbling in space. Gaspra became one of the best-studied asteroids in 1991 when the spacecraft Galileo flew by. In the above photograph , subtle…
M64: The Sleeping Beauty Galaxy
The Sleeping Beauty galaxy may appear peaceful at first sight but it is actually tossing and turning. In an unexpected twist, recent observations have shown that the center of…
NGC 1531/2: Interacting Galaxies
This dramatic image of an interacting pair of galaxies was made using the 1.5 meter telescope at the Cerro Tololo Inter-American Observatory near La Serena, Chile. NGC 1531 is the…
Hale-Bopp: The Crowd Pleaser Comet
In 1997, the bright comet Hale-Bopp may have become the most viewed comet in history -- visible even to casual skywatchers in light polluted cities around the globe . In this…
Mysterious Pluto and Charon
Pluto is the only planet in our Solar System remaining unphotographed by a passing spacecraft. Distant Pluto and its moon Charon therefore remain somewhat mysterious. In addition…
M8: The Lagoon Nebula
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…
Sizzling Io
What's cooking on Io ? This active moon of Jupiter is marked with volcanoes spewing lava that is now known to be hotter than any lava on Earth . Above is the highest resolution…
Apollo 15's Home on the Moon
Could you ever call this place home? The lunar module shown above, named “Falcon,” served as home for Apollo 15 astronauts David Scott and James Irwin during their stay on the…
The Firework Nebula
Imaged by the WIYN Telescope, the Firework Nebula is the result of a type of stellar explosion called a nova. In a nova , a nuclear detonation on the surface of a compact white…
Mir Above
Photographed from the approaching Space Shuttle Endeavour , the Mir space station floats above the clouds of planet Earth. Mir's modular construction , bristling with solar panels…
X-ray Transit Of Mercury
This sequence of false color X-ray images captures a rare event - the passage or transit of planet Mercury in front of the Sun. Mercury's small disk is silhouetted against the…
NGC 1808: A Nearby Starburst Galaxy
NGC 1808 is a galaxy in turmoil. A barred spiral with marked similarities to our home Milky Way Galaxy , NGC 1808 is distinguished by a peculiar nucleus , an unusually warped disk…
The Universe Evolves
Scroll right and watch the universe evolve. Above is a computer simulation depicting the evolution of our entire universe. On the far left is a slice of the universe soon after…
Solar Magnetic Bananas
Is that our Sun ? The unusual banana -shaped loops shown above are actually part of a computer-generated snap-shot of our Sun's magnetic field . This animated frame was…
Comet Hale-Bopp Over Val Parola Pass
In 1997, Comet Hale-Bopp became much brighter than any surrounding stars. It could be seen even over bright city lights. Out away from city lights, however, it put on quite a…
Southern Neptune
Neptune , the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. Twelve years after a 1977 launch , Voyager 2 flew by Neptune and found…
A Planet For Gliese 876
Centered in this unremarkable, 1/4 degree wide patch of sky in the constellation Aquarius is the star Gliese 876. Gliese 876 is smaller than the Sun, only about 1/3 as massive,…
NGC 4650A: Strange Galaxy and Dark Matter
This strangely distorted galaxy of stars is cataloged as NGC 4650A. It lies about 165 million light-years away in the southern constellation Centaurus . The complex system seems…
Sparkling Star May Indicate Galactic Composition
If a star in this photograph twinkled slightly, would anyone notice? Would anyone care? Astronomers with the MACHO Collaboration noticed one such twinkle just last week, and many…
Viewing discoveries from 17 July 1998 through 24 June 1998.