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.
Beneath the South Pole of Saturn
What clouds lurk beneath Saturn's unusual South Pole? To help find out, the robotic Cassini spacecraft currently orbiting Saturn imaged the nether region of the gigantic ringed…
Massive Stars in Open Cluster Pismis 24
How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of…
NGC 602 and Beyond
Near the outskirts of the Small Magellanic Cloud , a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal…
Amazing Comet Holmes
One year ago , Comet 17P/Holmes amazed sky watchers across planet Earth. A stunningly rapid outburst transformed it from a faint comet quietly orbiting the Sun with a period of…
Great Orion Nebulae
The Great Nebula in Orion , also known as M42, is one of the most famous nebulae in the sky. The star forming region's glowing gas clouds and hot young stars are on the right in…
Beautiful Spiral NGC 7331
A favorite target for astronomers, big, beautiful spiral galaxy NGC 7331 is one of the brighter galaxies not found in Charles Messier's famous 18th century catalog. About 50…
A Dark Pulsar in CTA 1
Where's the pulsar? Previously, the nebula CTA 1 showed an expanding supernova remnant , a jet , and a point source expected to be a pulsar -- a rotating neutron star producing…
Moons, Rings, and Unexpected Colors on Saturn
Why would Saturn show such strange colors? The robotic Cassini spacecraft currently orbiting Saturn has beamed back images showing that the northern hemisphere our Solar System 's…
In the Center of the Lagoon Nebula
The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible on the upper left, at least two long funnel-shaped clouds, each roughly half a light-year…
Sharpless 171
Cosmic pillars of cold molecular gas and clouds of dark dust lie within Sharpless 171, a star-forming region some 3,000 light-years away in the royal constellation Cepheus . This…
An Extraordinary Voyage
Nineteenth century science fiction author Jules Verne wrote visionary works about Extraordinary Voyages including tales of space flight and the story of a journey From the Earth…
48 Years of Space Flight
This year, NASA celebrated its 50th anniversary . Inspired to make his own contribution, astronomer Ralf Vandebergh set out to record images of some historic spacecraft in Earth…
Camera Orion
Orion , the Hunter, is one of the most easily recognizable constellations in planet Earth's night sky . But Orion's stars and nebulas don't look quite as colorful to the eye as…
An Enceladus Tiger Stripe from Cassini
What creates the unusual tiger stripes on Saturn's moon Enceladus? No one is sure. To help find out, scientists programmed the robotic Cassini spacecraft to dive right past the…
Cassini Passes Through Ice Plumes of Enceladus
What telling impurities taint the ice plumes of Enceladus? To help answer this question, the robotic Cassini spacecraft dove last week to within 30 kilometers of Saturn's…
Spiral Galaxy NGC 3370 from Hubble
Is this what our own Milky Way Galaxy looks like from far away? Similar in size and grand design to our home Galaxy (although without the central bar), spiral galaxy NGC 3370 lies…
Bright Bolide
On September 30, a spectacular bolide or fireball meteor surprised a group of amateur astronomers enjoying dark night skies over the Oklahoma panhandle's Black Mesa State Park in…
Irregular Galaxy NGC 55
Irregular galaxy NGC 55 is thought to be similar to the Large Magellanic Cloud (LMC). But while the LMC is about 180,000 light-years away and is a well known satellite of our own…
Massive Stars in NGC 6357
Massive stars lie within NGC 6357 , an expansive emission nebula complex some 8,000 light-years away in the tail of the constellation Scorpius . In fact, positioned just below…
Mercury as Revealed by MESSENGER
The planet Mercury has been known since history has been recorded, but parts of the Solar System's innermost planet have never been seen like this before. Two days ago the robotic…
Dust Mountains in the Carina Nebula
Bright young stars sometimes sculpt picturesque dust mountains soon after being born. Created quite by accident, the energetic light and winds from these massive newborn stars…
Layers of Red Cliffs on Mars
How did these layers of red cliffs form on Mars? No one is sure. The northern ice cap on Mars is nearly divided into two by a huge division named Chasma Boreale . No similar…
Earth at Night
This is what the Earth looks like at night. Can you find your favorite country or city ? Surprisingly, city lights make this task quite possible. Human-made lights highlight…
A Solar Prominence Unfurls
On September 29, this magnificent eruptive solar prominence lifted away from the Sun's surface, unfurling into space over the course of several hours. Suspended in twisted…
Viewing discoveries from 27 October 2008 through 4 October 2008.