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.
Slightly Above Mars Pathfinder
If you could have hovered above the Pathfinder mission to Mars in 1997, this is what you might have seen. Directly below you is the control tower of Sagan Memorial Station . Three…
Antarctic Ozone Hole Widens
It's back, and it's bigger than ever. The ozone hole that has been a cause of concern in recent years has again reformed over Earth's South Pole . The seasonal recur rence of the…
White Dwarf Stars Cool
Diminutive by stellar standards , white dwarf stars are also intensely hot ... but they are cooling. No longer do their interior nuclear fires burn , so they will continue to cool…
X-Ray Moon and X-Ray Star
An x-ray star winks out behind the Moon in these before (left) and after views of a lunar occultation of the galactic x-ray source designated GX5-1 . The false color images were…
Andromeda Island Universe
How far can you see? The most distant object easily visible to the unaided eye is M31 , the great Andromeda Galaxy some two million light-years away. Without a telescope, even…
IC 418: The Spirograph Nebula
What is creating the strange texture of IC 418? Dubbed the Spirograph Nebula for its resemblance to drawings from a cyclical drawing tool , planetary nebula IC 418 shows patterns…
Emerging Planetary Nebula CRL 618
CRL 618 may look to some like an Olympian declaring victory. Only a few hundred years ago, however, CRL 618 appeared as a relatively modest red giant star . Since then it has run…
CFHT Star Trails
High atop a dormant volcano in Hawaii , an eye 3.6-meters wide stares at a faint light on the night sky. Unlike a human eye , which collects light for only a fraction of a second…
Aurora Persei
Last month, skywatchers were treated to an unexpected coincidence: bright aurorae occurred during the Perseid Meteor Shower . The above picture was taken August 12 and captures…
Henrietta Leavitt Calibrates the Stars
Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College…
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.…
SOHO Sungrazer
SOHO , the space-based SOlar and Heliospheric Observatory, has become by far the reigning champion facility for discovering comets, its total having recently reached 200 . As…
Full Throttle For Deep Space 1
At full throttle the Deep Space 1 spacecraft's innovative ion drive produces about 1/50th of a pound of thrust ... a force so great that it would just about hold up a piece of…
The Brown Dwarfs of Orion's Trapezium
The bright stars above are well known as heart of the Trapezium , an open cluster of stars in the center of the Orion Nebula . The many dim objects, however, are not well known,…
The Regolith of Asteroid Eros
From fifty kilometers above asteroid Eros, the surface inside one of its largest craters appears covered with an unusual substance: regolith . The thickness and composition of the…
The Helix Nebula from CFHT
One day our Sun may look like this. The Helix Nebula is the closest example of a planetary nebula created at the end of the life of a Sun-like star. The outer gasses of the star…
Orion's Horsehead Nebula
The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the black indentation to the red emission nebula seen just to the right of center of the above…
Mir Dreams
This dream-like image of Mir was recorded by astronauts as the Space Shuttle Atlantis approached the Russian space station prior to docking during the STS-76 mission . Sporting…
Folding Europa
Astypalaea Linea on Jovian ice moon Europa is the broad smooth region running through these images recorded by the Galileo spacecraft in 1998. The pictures are different computer…
Eros At Sunset
Gleaming in the rays of the setting sun, boulders litter the rugged surface of asteroid 433 Eros . The brightest boulder, at the edge of the large, shadowy crater near this…
NGC 6960: The Witch's Broom Nebula
Ten thousand years ago, before the dawn of recorded human history , a new light must suddenly have appeared in the night sky and faded after a few weeks. Today we know this light…
NGC 2244: A Star Cluster in the Rosette Nebula
In the heart of the Rosette Nebula lies a bright open cluster of stars that lights up the nebula. The stars of NGC 2244 formed from the surrounding gas only four million years ago…
A Perseid Aurora
Just after the Moon set but before the Sun rose in the early morning hours of August 12, meteors pelted the Earth from the direction of the constellation Perseus , while ions…
The Surface of Titan
If sailing the hydrocarbon seas of Titan , beware of gasoline rain. Such might be a travel advisory issued one future day for adventurers visiting Titan , the largest moon of…
Viewing discoveries from 12 September 2000 through 20 August 2000.