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.
Early Microscopic Life on Mars?
Today a team of NASA and Stanford scientists announced the discovery of strong circumstantial evidence that microscopic life once existed on Mars . Dr. David McKay, Dr. Everett…
Europa: Oceans of Life?
Is there life beneath Europa's frozen surface? Some believe the oceans found there of carbon-enriched water are the best chance for life , outside the Earth , in our Solar System…
Erupting Volcanoes on Io
Jupiter's moon Io has active volcanoes. The Voyager spacecraft caught several erupting when they passed the energetic moon in 1979. In the above picture, several of Io's volcanoes…
NGC 3393: A Super Spiral?
A bird? A plane? No, but pictured here is something physically much larger, flying much higher, and moving much faster than either of these. It is, in fact, a Seyfert type 2…
Jupiter's Colorful Clouds
What makes the colors in Jupiter's clouds ? With a mean temperature of 120 degrees Kelvin (-153 degrees Celsius) and a composition dominated by Hydrogen (about 90%), and Helium…
Galileo, Cassini, and the Great Red Spot
Imagine a hurricane that lasted for 300 years! Jupiter's Great Red Spot indeed seems to be a giant hurricane-like storm system rotating with the Jovian clouds. Observed in 1655 by…
The Hydra Cluster of Galaxies
You are flying through space and come to ... the Hydra Cluster of Galaxies. Listed as Abell 1060, the Hydra Cluster contains well over 100 bright galaxies. Clusters of galaxies…
A Violet Moon
Checking out the Galileo spacecraft's cameras during its December 1992 flyby of Earth's Moon, controllers took this dramatically illuminated picture through a violet filter. The…
Tonight: A Blue Moon
How often does a Full Moon occur twice in a single month? Exactly once in a Blue Moon . In fact, the modern usage of the term “Blue Moon” refers to the second Full Moon in a…
A Dust Jet From Hale-Bopp
Approaching the inner Solar System, comet Hale-Bopp 's icy nucleus is heated by sunlight, accelerating its production of dust and gas. Shrouded in the resulting cloud, known as…
Huck Finn's New Sky View
Even the faintest stars Huck and Jim could see as their raft drifted down the Mississippi were in our own Galaxy . The faintest objects astronomers can see today are the distant…
Driving to the Sun
How long would it take to drive to the Sun? Brittany, age 7, and D.J., age 12, ponder this question over dinner one evening. James, also age 7, suggests taking a really fast…
The Cygnus Loop
15,000 years ago a star in the constellation of Cygnus exploded -- the shockwave from this supernova explosion is still expanding into interstellar space! The collision of this…
Hale-Bopp on Schedule
Late March and early April of 1996 marked a banner season for viewing the spectacular naked-eye comet Hyakutake . The spring of 1997 could well offer a similar cometary wonder,…
COMPTEL Explores The Radioactive Sky
Diffuse gas clouds laced with radioactive aluminum atoms (Al26) line the plane of our Milky Way Galaxy! How do we see them? Relying on the Compton Effect , the COMPTEL instrument…
Hale-Bopp, Jupiter, and the Milky Way
Shining brightly, the mighty Jupiter rules this gorgeous Kodacolor photo of the Milky Way near Sagittarius . Astronomer Bill Keel took the picture earlier this month (July 7)…
Utopia on Mars
The Viking 2 spacecraft was launched on the Road to Utopia in September of 1975 (30 years after Bing, Dotty, and Bob). In August of 1976, after making the second successful…
The Eagle Soars
On July 21, 1969 Apollo 11 astronauts Neil A. Armstrong and Edwin E. “Buzz” Aldrin Jr. lifted off the lunar surface in the ascent stage of their lunar module dubbed “The Eagle” --…
20 Years Ago: Vikings on Mars
On July 20, 1976 , NASA's Viking 1 lander become the first spacecraft to land on Mars , followed weeks later by its twin robot explorer, the Viking 2 lander. Operating on the…
Galileo's First Color Image of Io
Above is the first color image of Jupiter's volcanic moon Io released by the Galileo Project. (Io sounds like “eye-oh”.) The image was made on June 25 when the Galileo spacecraft…
Nebulosity in Sagittarius
What causes the colors in this beautiful nebulosity in Sagittarius? Dubbed NGC 6589 and NGC 6590, the colors of this nebulosity, are caused by gas and dust . The blue color of the…
Looking Down on Saturn
This picture of Saturn could not have been taken from Earth . No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn's…
A Portrait of Saturn from Titan
The above artistic portrait of Saturn depicts how it might look from Titan , Saturn's largest moon. In the foreground sits ESA's Huygens probe , which will be released by NASA's…
Keck: The Largest Optical Telescope
In buildings eight stories tall rest mirrors ten meters across that are slowly allowing humanity to map the universe. Alone, each is the world's largest optical telescope : Keck .…
Viewing discoveries from 7 August 1996 through 15 July 1996.