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.
Callisto Full Face
Callisto 's surface shows its age. While probably formed at the same time as Io , the difference between the surfaces of these two moons of Jupiter could hardly be greater. Io's…
Stars Without Galaxies
Galaxies are made up of stars, but are all stars found within galaxies? Using the Hubble Space Telescope, researchers exploring the Virgo Cluster of galaxies have found about 600…
Saturn and Vesta in Taurus
Last November, while skygazing toward the constellation Taurus , astrophotographer Joe Orman arranged this time exposure to include the lovely Hyades and Pleiades star clusters in…
Pick a Galaxy, Any Galaxy
Pick a galaxy , any galaxy. In the top panel you can choose from a myriad of distant galaxies revealed in a deep Hubble Space Telescope image of a narrow slice of the cosmos…
Abell 2597's Cosmic Cavities
Typical of large galaxy clusters billions of light-years away, Abell 2597 features hundreds of galaxies embedded in a cloud of multimillion degree gas which glows in x-rays. This…
Red Auroral Corona
Few auroras show this level of detail. This unusual display of an auroral corona occurred on Earth three days after an unusual solar event -- the fifth most powerful explosion yet…
Sun Halo at Winter Solstice
Sometimes it looks like the Sun is being viewed through a large lens . In the above case, however, there are actually millions of lenses: ice crystals . As water freezes in the…
Hypatia of Alexandria
Sixteen hundred years ago, Hypatia became one of the world's leading scholars in mathematics and astronomy. Hypatia 's legendary knowledge, modesty, and public speaking ability…
The Gamma Ray Sky
What if you could see gamma rays ? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe. In…
Sunbather
Intense and overwhelming, the direct glare of the Sun is blocked by the smooth disk centered in this image from the sun-staring SOHO spacecraft. Taken on January 8, the picture…
X-Ray Milky Way
If you had x-ray vision, the center regions of our Galaxy would not be hidden from view by immense cosmic dust clouds opaque to visible light. Instead , the Milky Way toward…
Blue Flash
Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending or refraction of sunlight.…
Thackeray's Globules
Rich star fields and glowing hydrogen gas silhouette dense, opaque clouds of interstellar gas and dust in this Hubble Space Telescope close-up of IC 2944 , a bright star forming…
The Mysterious Cone Nebula
Sometimes the simplest shapes are the hardest to explain. For example, the origin of the mysterious cone-shaped region seen on the far left remains a mystery. The interstellar…
M2-9: Wings of a Butterfly Nebula
Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and…
Apollo 17's Moonship
Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the vacuum of space. This sharp picture from the command module America , shows…
M16: Infrared Star Hunt
The head of an interstellar gas and dust cloud is shown here in false-color, a near-infrared view recorded by astronomers hunting for stars within M16's Eagle Nebula . Made famous…
M16: Stars, Pillars, and the Eagle's EGGs
The Hubble Space Telescope's 1995 image of pillars of dust and gas, light-years long, within the Eagle Nebula ( M16 ) was sensational. The three prominent pillars in that close-up…
International Space Station Over Earth
High above a cloudy Earth, the International Space Station (ISS) orbits silently. The Space Shuttle Endeavor Crew took the above picture as they departed the space station in…
The Secret of the Black Aurora
What causes black aurora? These gaps in normal bright aurora are frequently recorded but rarely questioned. Recent research using data from four Cluster spacecraft orbiting the…
A Year of Dark Cosmology
We live in the exciting time when humanity discovers the nature of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears…
Trifid Pillars & Jets
Dust pillars are like interstellar mountains . They survive because they are more dense than their surroundings, but they are being slowly eroded away by a hostile environment.…
The Annotated Galactic Center
The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders . Many are easily visible with binoculars. Constellations near the galactic center…
Starlight Reflections
Interstellar dust grains often find themselves in a reflective “mood”. Near a bright star, clouds of these dust particles scatter short wavelengths of visible starlight more…
Viewing discoveries from 20 January 2002 through 28 December 2001.