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.
Dust Hip-Deep on Phobos
Landing on the Martian Moon Phobos might be harder than previously thought. The reason: Moon dust . Recent photographs of Phobos have indicated that a layer of fine powder…
Galileo Demonstrates the Telescope
Galileo Galilei made a good discovery great. Upon hearing at age 40 that a Dutch optician had invented a glass that made distant objects appear larger, Galileo crafted his own…
Star Trails in Northern Skies
As the Earth spins on its axis, the sky seems to rotate around us. This motion produces the beautiful concentric trails traced by the stars in this time exposure of the night sky.…
Help Map The Moon
You can help map the Moon . Early tomorrow morning (Saturday, September 12) the Moon will occult , or pass in front of, the bright star Aldebaran as viewed from some Southern and…
Europa: Ridges and Rafts on a Frozen Moon
The large Jovian moon Europa may harbor liquid water beneath its frozen crust . Controversy surrounding this idea has been recently fueled by dramatic images of Europa's surface…
Crater Copernicus
One of the more prominent craters on the Moon is named Copernicus . Copernicus is a large young crater visible with binoculars slightly northwest of the center of the Moon's…
A Cluster Too Far
Why is this galaxy cluster so red? Nearby clusters have galaxies with colors that are much more yellow and blue. A leading explanation is that this cluster of galaxies lies so far…
The Sky Towards Sagittarius
A variety of stars and nebulae can be found towards the constellation of Sagittarius . Dense fields of stars laced with dark lanes of dust crowd this region only a few degrees…
Mariner's Mercury
Mercury , the closest planet to the Sun, remains the most mysterious of the Solar System's inner planets. Hiding in the Sun's glare it is a difficult target for Earth bound…
The Pulsar Powered Crab
In the Summer of 1054 A.D. Chinese astronomers reported that a star in the constellation of Taurus suddenly became as bright as the full Moon. Fading slowly, it remained visible…
Nozomi: Earth and Moon
Japan launched its first mission to orbit Mars, Nozomi (Hope) , on July 3rd from the Kagoshima Space Center on the island of Kyushu . Nozomi's goal is to explore the Martian…
SGR 1900+14: Magnetar
On August 27th an intense flash of X-rays and gamma-rays swept through our Solar System. Five spacecraft of the Third InterPlanetary gamma-ray burst Network , Ulysses , WIND ,…
Saturn from Earth
Saturn is the second largest planet in our Solar System . Saturn has been easily visible in the sky since history has been recorded. Galileo used one of the first telescopes in…
A Colorful Aurora
A solar storm overtook the Earth on August 26th. The Earth survived unscathed, as usual, although many northerners reported an impressive display of aurora . Many of these auroras…
A3827: Galactic Cannibal
It was mealtime in galaxy cluster Abell 3827. The hungry cluster dominant galaxy in A 3827's center is seen being fed. Breakfast included five smaller galaxies unfortunate enough…
The Sun Erupts
The Sun is a seething ball of extremely hot gas. Above, the Sun was captured by Skylab in 1973 throwing off one the largest eruptive prominences in recorded history. The Sun has…
Orion Star Colours
What determines a star's colour? Its temperature . Red stars are cool, around 3,000 kelvins (K), while blue stars are hotter and can have temperatures over 30,000 K. Our own…
Hydrogen Trifid
Clouds of glowing hydrogen gas mingle with dark dust lanes in the Trifid Nebula , a star forming region in the constellation Sagittarius. In this and other similar emission…
Hercules Galaxies
These are galaxies of the Hercules Cluster , an archipelago of “island universes” a mere 650 million light-years distant. This cluster is loaded with gas and dust rich, star…
The Magellanic Stream
Spanning the sky behind the majestic Clouds of Magellan is an unusual stream of gas: the Magellanic Stream . The origin of this gas might hold a clue to origin and fate of our…
Moon, Venus, Jupiter, Phoenix
Before a relaxing sunrise, the sky begins to glow with unusual delights. Such was the view from Papago Park in Phoenix , Arizona this April. The glittering objects visible in this…
An Annular Eclipse of the Sun
An annular eclipse of the Sun was visible in parts of the Eastern Hemisphere on Saturday. The above picture was taken at that time by a video camera in Mersing on the East Coast…
Vega
Vega is a bright blue star 25 light years away. Vega is the brightest star in the Summer Triangle , a group of stars easily visible summer evenings in the northern hemisphere. The…
Twistin' by the Lagoon
The awesome spectacle of starbirth produces extreme stellar winds and intense energetic starlight -- bombarding dusty molecular clouds inside the Lagoon Nebula ( M8 ). At least…
Viewing discoveries from 14 September 1998 through 22 August 1998.