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.
A Force from Empty Space: The Casimir Effect
This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to…
An Atlas V Rocket Prepares to Launch
The first launch of an Atlas V rocket occurred last month. The Atlas V , built by Lockheed Martin , is the first rocket in the U. S. Air Force 's Evolved Expendable Launch Vehicle…
Zodiacal Light and the False Dawn
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once…
X-Ray Moon
This x-ray image of the Moon was made by the orbiting ROSAT ( Röntgensatellit ) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity.…
Aristarchus Plateau
Anchored in the vast lava flows of the Moon's Oceanus Procellarum lies the Aristarchus Plateau . Recorded from a backyard observatory on planet Earth, this sharp, amazingly…
X-Rays From Tycho's Supernova Remnant
In 1572, Danish astronomer Tycho Brahe recorded the sudden appearance of a bright new star in the constellation Cassiopeia. The new star faded from view over a period of months…
Pluto & Charon Eclipse a Triple Star
Occasionally, a planet in our Solar System will pass in front of a bright star. Since stars and planets take up so little space on the sky, such events are quite rare. Two months…
Venus Beyond the Storm
A thunderstorm, lightning, a bright star and a bright planet all graced an evening sky for a short while near Bismarck , North Dakota , USA two weeks ago. Thick thunderclouds from…
Hoag's Object: A Strange Ring Galaxy
Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by…
Too Close to a Black Hole
What would you see if you went right up to a black hole ? Above are two computer generated images highlighting how strange things would look. On the left is a normal star field…
Stereo Saturn
Get out your red/blue glasses and launch yourself into this stereo picture of Saturn! The picture is actually composed from two images recorded weeks apart by the Voyager 2…
HESS Gamma-Ray Telescope
Most ground-based telescopes with lenses and mirrors are hindered by the Earth's nurturing, protective atmosphere that blurs images and scatters and absorbs light. But this…
Voyager Views Titan's Haze
Launched in 1977, 25 years ago today, the Voyager 1 spacecraft's historic tour of the outer Solar System took it past Saturn in late 1980. On November 12, 1980, Voyager 1 recorded…
Halo of the Cat's Eye
The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky . Its haunting symmetries are seen in the very central region of this stunning false-color…
A Dust Devil on Mars
Does the surface of Mars change? When inspecting yearly images of the Martian surface taken by the robot spacecraft Mars Global Surveyor currently orbiting Mars , sometimes new…
Colorful Light Pillars
How can an aurora appear so near the ground? Pictured above are not aurora but nearby light pillars , a local phenomenon that can appear as a distant one. In most places on Earth,…
The Hubble Deep Field
Galaxies like colorful pieces of candy fill the Hubble Deep Field - one of humanity's most distant optical views of the Universe . The dimmest, some as faint as 30th magnitude…
The Voyagers' Message in a Bottle
Launched twenty-five years ago , NASA's Voyager 1 and 2 spacecraft are now over 10 billion kilometers from the Sun. Still operational , the Voyagers are being tracked and…
Semeis 147: Supernova Remnant
It's easy to get lost following the intricate filaments in this stunningly detailed image of faint supernova remnant Simeis 147. Seen towards the constellation Taurus it covers…
The Pelican in the Swan
The Pelican Nebula, also known as IC 5070, lies about 2,000 light-years away in the high and far-off constellation of Cygnus, the Swan . This picture spans a portion of the…
3D Mars: Northern Terra Meridiani
In this spectacular 3D stereoscopic view from orbit , steep-sided, flat-topped hills stand above the Terra Meridiani region of Mars. Seen best with red/blue glasses (red for the…
Valles Marineris: The Grand Canyon of Mars
The largest canyon in the Solar System cuts a wide swath across the face of Mars . Named Valles Marineris , the grand valley extends over 3,000 kilometers long, spans as much as…
The Mysterious Voynich Manuscript
The ancient text has no known title, no known author, and is written in no known language: what does it say and why does it have many astronomy illustrations? The mysterious book…
Nebula Nova Cygni Turns On
Old photographs show no evidence of the above nebula. In 1992, a white dwarf star toward the constellation of Cygnus blew off its outer layers in a classical nova explosion: an…
Viewing discoveries from 17 September 2002 through 25 August 2002.