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.
Hyakutake, Venus, Orion, and Pond
Can you find Comet Hyakutake in the above picture? In this gorgeous photo, the starry night sky of April 9th is pictured with its new comet visitor. In the foreground is a pond…
NGC 7293: The Helix Nebula
The Helix nebula (New General Catalog number 7293) is estimated to be a mere 450 light-years from the Sun, in the direction of the constellation Aquarius . At that distance it may…
Cometary Knots in the Helix Nebula
Four hundred fifty light-years from Earth, the wind from a dying, sun-like star produced a planetary nebula popularly known as the Helix . While exploring the Helix's gaseous…
NASA Mission to MAP the Universe
What is our universe made of? How rapidly is our universe expanding? When did galaxies form? These questions, among the most important and baffling to astronomers since the…
The Rotating Jets of Comet Hyakutake
Comet Hyakutake will reach its closest point to the Sun on May 1, passing well inside the orbit of Mercury . At this time, the comet's dust and ion tail will be at their greatest…
The Compton Observatory Turns Five
Earlier this April, NASA's Compton Gamma Ray Observatory , completed its fifth successful year in orbit, exploring the gamma ray sky . Pictured is astronaut Jay Apt perched in the…
Man Enters Space
Thirty five years ago today, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human in space. On April 12, 1961, his remotely controlled Vostok 1 spacecraft lofted him…
Unexpected X-rays from Comet Hyakutake
The first X-rays ever detected from a comet were discovered from Comet Hyakutake with the ROSAT satellite on March 27th. The discovery is particularly surprising because there was…
Comet Hyakutake and a Tree
Comet Hyakutake is still visible as it continues its orbit around the Sun . The comet will brighten again in late April and early May. The above fascinating picture was taken with…
A Spiral Galaxy Gallery
A progression of beautiful spiral galaxies is illustrated above with three photographs from NASA's Ultraviolet Imaging Telescope (UIT). Flying above the Earth's obscuring layer of…
Uranus's Moon Oberon: Impact World
Oberon is the most distant and second largest moon of Uranus. Discovered by William Herschel in 1787, the properties of the world remained relatively unknown until the robot…
Uranus's Moon Umbriel: A Mysterious Dark World
Why is Umbriel so dark? This dark moon reflects only half the light of other Uranus' moons such as Ariel . And what is that bright ring at the top? Unfortunately, nobody yet…
Andromeda Nebula: Var!
In the 1920s, using photographic plates made with the Mt. Wilson Observatory's 100 inch telescope, Edwin Hubble determined the distance to the Andromeda Nebula - decisively…
The Perseus Cluster of Galaxies
Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy , together making up the Perseus Cluster, one of…
The Keyhole Nebula Near Eta Carinae
The dark dusty Keyhole Nebula gets its name from its unusual shape. Designated NGC 3324, the Keyhole Nebula is a smaller region superposed on the bright Eta Carina Nebula . The…
A Lucky Lunar Eclipse
Tonight's full moon would normally washout the spectacle of Comet Hyakutake's lovely tail , even for those far from light polluted skies. Except that tonight comet observers are…
Atlantis Approaches Mir
Imagine flying though space and approaching the Mir space station . The crew of the Space Shuttle Atlantis did just this in a mission that ended only two days ago. Mir, now 10…
Hyakutake, Big Dipper, and Observatory Dome
In one of the more spectacular pictures yet taken, Comet Hyakutake is shown here on March 26 high in the dark Missouri sky. In the foreground is Elmcrest Observatory complete with…
Comet Hyakutake Finder Chart for April
During April Comet Hyakutake heads in toward the Sun after passing the Earth . At this time the comet's orbit places it north of the Earth. Remaining visible in the northern sky…
An Extreme UltraViolet View of the Comet
As the Sun floods Comet Hyakutake with ultraviolet light gases in the coma scatter the radiation and fluoresce making the comet a bright source in the ultraviolet sky. The above…
The Colors of Comet Hyakutake
The colors of Comet Hyakutake are caused by the action of sunlight on the dust and gas produced by the warming nucleus . The microscopic dust particles reflect sunlight while the…
Near the Nucleus of Hyakutake
NASA's Hubble Space Telescope captured this image of the near-nuclear region of Comet Hyakutake on March 25 as the comet approached within 9.3 million miles of the Earth. It…
How Much is That Comet in the Window?
The above true-color photo taken March 25th shows Comet Hyakutake passing below the stars of the Big Dipper . Many astronomy enthusiasts delight in helping people in their local…
What are Comet Tails Made Of?
The tail of comet Hyakutake , visible in this recent color image , is composed of dust and gas driven off the icy comet nucleus by the Sun's heat and blown away by the solar wind.…
Viewing discoveries from 18 April 1996 through 26 March 1996.