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.
Sunset at the Portara
Today, the Sun crosses the celestial equator heading north at 11:44 UT . Known as an equinox, this astronomical event marks the first day of spring in the northern hemisphere and…
Saturn: Moons in Transit
Every 14 to 15 years, Saturn's rings are tilted edge-on to our line of sight. As the bright, beautiful rings seem to grow narrower it becomes increasingly difficult to see them,…
GLOBE at Night: Help Track Light Pollution
How many stars can you see? Through next week, the GLOBE at Night project invites people from all over the world to go outside at night, look up, and see! Specifically, people are…
Tycho's Supernova Remnant
What star created this huge puffball? Pictured above is the best multi-wavelength image yet of Tycho's supernova remnant , the result of a stellar explosion first recorded over…
Martian Moon Deimos from MRO
Mars has two tiny moons, Phobos and Deimos . Pictured above , in a recently release image by HiRISE camera onboard the Mars-orbiting Mars Reconnaissance Orbiter (MRO), is Deimos ,…
A Prominent Solar Prominence from SOHO
What's happened to our Sun? It was sporting a spectacular -- but not very unusual -- solar prominence. A solar prominence is a cloud of solar gas held above the Sun's surface by…
Haute-Provence Star Trails
Fix your camera to a tripod and you can record the graceful trails traced by the stars as planet Earth rotates on its axis . For example, this dramatic 5 hour long exposure was…
Hickson Compact Group 90
Scanning the skies for galaxies, Canadian astronomer Paul Hickson and colleagues identified some 100 compact groups of galaxies , now appropriately called Hickson Compact Groups…
Thor's Helmet (NGC 2359) and Planetary Nebula
At the right, Thor's Helmet (NGC 2359) seems to gaze across a lovely star field. The broad skyscape itself covers about 1.5 degrees or 3 full moons toward the constellation Canis…
Lunar X
The striking X near the center of this lunarscape is easily visible in binoculars or a small telescope. Yet, not too many have seen it. The catch is, this lunar X is only apparent…
Horsehead and Orion Nebulae
Adrift 1,500 light-years away in one of the night sky's most recognizable constellations , the glowing Orion Nebula and the dark Horsehead Nebula are contrasting cosmic vistas.…
Kepler's Streak
Streaking skyward , a Delta II rocket carries NASA's Kepler spacecraft aloft into the clear night of March 6. The dramatic scene was recorded in a time exposure from the crowded…
Gibbous Europa
Although the phase of this moon might appear familiar, the moon itself might not. In fact, this gibbous phase shows part of Jupiter 's moon Europa . The robot spacecraft Galileo…
Comet Lulin and Distant Galaxies
Now fading in our night sky, Comet Lulin has provided some lovely cosmic vistas . Moving rapidly against the background of stars , Lulin briefly posed with the likes of Saturn ,…
Crescent Moon and Venus
Last Friday, the Moon and Venus shared the early evening sky in a beautiful conjunction. Separated by only about 2 degrees, they also were both in a crescent phase . Just like our…
IC 5146: The Cocoon Nebula
Inside the Cocoon Nebula is a newly developing cluster of stars. Cataloged as IC 5146 , the beautiful nebula is nearly 15 light-years wide, located some 4,000 light years away…
Saturn in View
Very good telescopic views of Saturn can be expected in the coming days as the ringed planet nears opposition on March 8th, its closest approach to Earth in 2009. Of course,…
The Helix Nebula from La Silla Observatory
Will our Sun look like this one day? The Helix Nebula is one of brightest and closest examples of a planetary nebula , a gas cloud created at the end of the life of a Sun-like…
Earthgrazer: The Great Daylight Fireball of 1972
What is that streaking across the sky? A bright earthgrazing meteor. In 1972, an unusually bright meteor from space was witnessed bouncing off Earth's atmosphere, much like a…
Omega Centauri: The Largest Nearby Globular Cluster
This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed , and even before our Earth existed, ancient globs of stars condensed and orbited…
NGC 2442: Galaxy in Volans
Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish , (Piscis) Volans . Located about 50 million light-years away, the galaxy's two spiral arms…
Lulin and Saturn near Opposition
Tracking through the constellation Leo on February 23rd, bright planet Saturn and Comet Lulin were both near opposition -- opposite the Sun in planet Earth's sky. They also passed…
Moon, Mercury, Jupiter, Mars
When the Moon rose in predawn skies on February 23rd, it sported a sunlit crescent. It also offered early morning risers a tantalizing view of earthshine , the dark portion of the…
Two Tails of Comet Lulin
Go outside tonight and see Comet Lulin. From a dark location, you should need only a good star map and admirable perseverance -- although wide-field binoculars might help.…
Viewing discoveries from 20 March 2009 through 25 February 2009.