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.
Comet Hale-Bopp Over Val Parola Pass
Comet Hale-Bopp , the Great Comet of 1997, became much brighter than any surrounding stars. It was seen even over bright city lights . Away from city lights, however, it put on…
Ninety Gravitational Wave Spectrograms and Counting
Every time two massive black holes collide , a loud chirping sound is broadcast out into the universe in gravitational waves . Humanity has only had the technology to hear these…
Space Station Silhouette on the Moon
What's that unusual spot on the Moon? It's the International Space Station . Using precise timing, the Earth-orbiting space platform was photographed in front of a partially lit…
Total Solar Eclipse Below the Bottom of the World
Yesterday there was a total solar eclipse visible only at the end of the Earth. To capture the unusual phenomenon , airplanes took flight below the clouded seascape of Southern…
Iridescent by Moonlight
In this snapshot from November 18, the Full Moon was not far from Earth's shadow . In skies over Sicily the brightest lunar phase was eclipsed by passing clouds though. The full…
Comet Leonard and the Whale Galaxy
Sweeping through northern predawn skies, on November 24 Comet Leonard (C/2021 A1) was caught between two galaxies in this composite telescopic image . Sporting a greenish coma the…
NGC 6822: Barnard's Galaxy
Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too,…
A Blue-Banded Blood Moon
What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however…
In Motion: Uranus and Moons
What's that moving across the sky? A planet just a bit too faint to see with the unaided eye: Uranus. The gas giant out past Saturn was tracked earlier this month near opposition…
The Extraordinary Spiral in LL Pegasi
What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase,…
A High Cliff on Comet Churyumov-Gerasimenko
This high cliff occurs not on a planet, not on a moon, but on a comet. It was discovered to be part of the dark nucleus of Comet Churyumov-Gerasimenko (CG) by Rosetta , a robotic…
Messier 101
Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this…
Great Refractor and Lunar Eclipse
Rain clouds passed and the dome of the Lick Observatory's 36 inch Great Refractor opened on November 19. The historic telescope was pointed toward a partially eclipsed Moon.…
At the Shadow's Edge
Shaped like a cone tapering into space, the Earth's dark central shadow or umbra has a circular cross-section. It's wider than the Moon at the distance of the Moon's orbit though.…
Pleiades: The Seven Sisters Star Cluster
Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the…
The Sun in X-rays from NuSTAR
Why are the regions above sunspots so hot? Sunspot s themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective…
Lunar Eclipse over a Skyscraper
Why is the Moon on top of this building? Planning . It took the astrophotographer careful planning -- including figuring out exactly where to place the camera and exactly when to…
Introducing Comet Leonard
Here comes Comet Leonard. Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars -- but its orbit will take the giant shedding…
An Almost Total Lunar Eclipse
Predawn hours of November 19 found the Moon in partly cloudy skies over Cancun, Mexico. Captured in this telephoto snapshot , the lunar disk is not quite entirely immersed in…
NGC 281: Starless with Stars
In visible light the stars have been removed from this narrow-band image of NGC 281 , a star forming region some 10,000 light-years away toward the constellation Cassiopeia. Stars…
Full Moonlight
A photographer in silhouette stands in bright moonlight as the Full Moon rises in this well-planned telephoto image. Of course, the Full Moon is normally the brightest lunar…
NGC 3314: When Galaxies Overlap
Why doesn't the nearby galaxy create a gravitational lensing effect on the background galaxy? It does, but since both galaxies are so nearby, the angular shift is much smaller…
Geminids from Gemini
Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is…
Light Pillar over Volcanic Etna
What happening above that volcano? Something very unusual -- a volcanic light pillar . More typically, light pillars are caused by sunlight and so appear as a bright column that…
Viewing discoveries from 8 December 2021 through 15 November 2021.