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.
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…
How to Identify that Light in the Sky
What is that light in the sky? Perhaps one of humanity's more common questions, an answer may result from a few quick observations. For example -- is it moving or blinking? If so,…
Rosetta's Comet in Gemini
Returning along its 6.4 year orbit, periodic comet Churyumov-Gerasimenko (67P) is caught in this telescopic frame from November 7. Sweeping past background stars in the…
M33: The Triangulum Galaxy
The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy . M33…
NGC 1333: Stellar Nursery in Perseus
NGC 1333 is seen in visible light as a reflection nebula , dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant…
Video of a Green Flash
Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the…
All of These Space Images are Fake Except One
Why would you want to fake a universe? For one reason -- to better understand our real universe . Many astronomical project s seeking to learn properties of our universe now start…
A Filament Leaps from the Sun
Why, sometimes, does part of the Sun's atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun's surface. Regions of strong surface…
The Cat's Eye Nebula in Optical and X-ray
To some it looks like a cat's eye. To others, perhaps like a giant cosmic conch shell. It is actually one of brightest and most highly detailed planetary nebula known, composed of…
The Galaxy Between Two Friends
On an August night two friends enjoyed this view after a day's hike on the Plateau d'Emparis in the French Alps. At 2400 meters altitude the sky was clear. Light from a setting…
The Dark Seahorse in Cepheus
Light-years across, this suggestive shape known as the Seahorse Nebula appears in silhouette against a rich, luminous background of stars. Seen toward the royal northern…
NGC 147 and NGC 185
Dwarf galaxies NGC 147 (left) and NGC 185 stand side by side in this sharp telescopic portrait. The two are not-often-imaged satellites of M31, the great spiral Andromeda Galaxy ,…
The Horsehead and Flame Nebulas
The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture .…
SN Requiem: A Supernova Seen Three Times So Far
We've seen this same supernova three times -- when will we see it a fourth? When a distant star explodes in a supernova , we're lucky if we see it even once. In the case of AT…
Viewing discoveries from 25 November 2021 through 2 November 2021.