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.
N159 and the Papillon Nebula
In a search for massive star s, the Hubble Space Telescope has peered into yet another spectacular region of star formation . This nebula, known as N159 , spans over 150…
Zodiacal Light
Sometimes the sky itself seems to glow. Usually, this means you are seeing a cloud reflecting sunlight or moonlight. If the glow appears as a faint band of light running across…
Venus: Just Passing By
Venus, the second closest planet to the Sun , is a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus…
AB Aurigae: How To Make Planets
This enhanced Hubble Space Telescope image shows in remarkable detail the inner portion of the disk of dust and gas surrounding the star AB Aurigae. Knots of material, visible…
Mjølnir: Impact Crater
The stark surface of Earth's moon is pocked with large craters, records of a history of fierce bombardment by the solar system's formative debris. It may be difficult to imagine,…
NGC 4414: A Telling Spiral
How far away is this galaxy? Cosmologists the world over have been working hard to find out. Spiral galaxy NGC 4414 contains many Cepheid variable stars that oscillate in a way…
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.…
Starbirth in the Trifid Nebula
Tremendous pillars of gas and dust are being boiled away in the Trifid Nebula . In the center of the picturesque Trifid lies a young hot star, located above and to the right of…
Kepler Discovers How Planets Move
Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe . Kepler was able…
Betelgeuse, Betelgeuse, Betelgeuse
Betelgeuse (sounds a lot like “beetle juice”), a red supergiant star about 600 light years distant, is seen in this Hubble Space Telescope image - the first direct picture of the…
NGC 3603: From Beginning To End
From beginning to end, different stages of a star's life appear in this exciting Hubble Space Telescope picture of the environs of galactic emission nebula NGC 3603 . For the…
Methane Dwarf
While hunting through Sloan Sky Survey data in search of distant quasars , Princeton astronomers Xiaohui Fan and Michael Strauss came upon an undiscovered type of object very…
Thermal Mars
It's 2 AM on Mars and surface temperatures range from -65C to -120C, as measured by the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor spacecraft. TES data…
A Gallery of Gravitational Mirages
The deeper you peer into the universe, the harder it is to see straight. The reason is that distant galaxies act as gravitational lenses , deflecting light that passes nearby.…
Uranus' Moon 18
The discovery was there for the taking. An image of Uranus taken by Voyager 2 as it passed the giant planet 13 years ago apparently recorded a moon that had since gone unnoticed.…
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…
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…
Topographical Mars
Contrasting colors trace changing elevations in this new high-resolution topographic map of Mars . Just released , the data were gathered in 1998 and 1999 by the Mars Orbiter…
NGC 4603 and the Expanding Universe
NGC 4603, a galaxy with majestic spiral arms and intricate dust lanes, is 108 million light-years away. Its distance has been accurately measured by astronomers using one of the…
GRB 990510: Another Unusual Gamma Ray Burst
Another huge explosion has lit up the universe, and astronomers are studying it as best they can before the light fades away. Two weeks ago, the BATSE instrument on the orbiting…
NGC 6872: A Stretched Spiral
What makes NGC 6872 so long? Measuring over 700,000 light years across from top to bottom, NGC 6872 is one of the largest barred spiral galaxies known. The galaxy's elongated…
Introducing Nova Velorum 1999
A bright nova was discovered Saturday that is currently visible to the unaided eye in southern skies. Nova Velorum 1999 was recorded near visual magnitude 3 independently by…
The Keyhole Nebula
The dark dusty Keyhole Nebula gets its name from its unusual shape. Officially designated NGC 3324, the Keyhole Nebula is a smaller region superposed on the larger Eta Carina…
M42: A Mosaic of Orion's Great Nebula
The Great Nebula in Orion , an immense, nearby starbirth region, is probably the most famous of all astronomical nebulae. Here, 15 pictures from the Hubble Space Telescope have…
Viewing discoveries from 14 June 1999 through 22 May 1999.