Astronomy Picture of the Day

photo 25 Brightest Stars in the Night Sky

25 Brightest Stars in the Night Sky

Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language. Many world cultures have their own names for the brightest ...

See full description

photo Anticrepuscular Rays Converge Opposite the Sun

Anticrepuscular Rays Converge Opposite the Sun

Is there ever anything interesting to see in the direction opposite the Sun? Sometimes there is. Notable items include your own shadow, a shadow of the Moon during a total solar eclipse, a full moon -- in eclipse if the alignment's good enough, a ...

See full description

photo Carina Nebula Panorama from Hubble

Carina Nebula Panorama from Hubble

How do violent stars affect their surroundings? To help find out, astronomers created a 48-frame high-resolution, controlled-color panorama of the center of the Carina Nebula, one of the largest star forming regions on the night sky. The featured ...

See full description


photo Ares 3 Landing Site: The Martian Revisited

Ares 3 Landing Site: The Martian Revisited

This close-up from the Mars Reconnaissance Orbiter's HiRISE camera shows weathered craters and windblown deposits in southern Acidalia Planitia. A striking shade of blue in standard HiRISE image colors, to the human eye the area would probably ...

See full description

photo Sunset Analemma

Sunset Analemma

Today, the solstice is at 15:54 Universal Time, the Sun reaching the northernmost declination in its yearly journey through planet Earth's sky. A June solstice marks the astronomical beginning of summer in the northern hemisphere and winter in ...

See full description

photo A View Toward M106

A View Toward M106

Big, bright, beautiful spiral, Messier 106 dominates this cosmic vista. The nearly two degree wide telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, ...

See full description

photo Our Galaxy's Magnetic Center

Our Galaxy's Magnetic Center

What's the magnetic field like in the center of our Milky Way Galaxy? To help find out, NASA's SOFIA -- an observatory flying in a modified 747 -- imaged the central region with an instrument known as HAWC+. HAWC+ maps magnetism by observing ...

See full description

photo Strawberry Moon over the Temple of Poseidon

Strawberry Moon over the Temple of Poseidon

Did you see the full moon last night? If not, tonight's nearly full moon should be almost as good. Because full moons are opposite the Sun, they are visible in the sky when the Sun is not -- which should be nearly all night long tonight, clouds ...

See full description

photo Milky Way over Pyramid of the Feathered Serpent

Milky Way over Pyramid of the Feathered Serpent

To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo -- in Mexico's Yucatán Peninsula -- near an equinox. Then, during the late afternoon if the sky is clear, the pyramid's own shadows ...

See full description

photo Unusual Mountain Ahuna Mons on Asteroid Ceres

Unusual Mountain Ahuna Mons on Asteroid Ceres

What created this unusual mountain? There is a new theory. Ahuna Mons is the largest mountain on the largest known asteroid in our Solar System, Ceres, which orbits our Sun in the main asteroid belt between Mars and Jupiter. Ahuna Mons, though, ...

See full description