Astronomy Picture of the Day

2010-08-31 Jaime Fernandez

The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders, many of which are visible from a dark location with common binoculars. Constellations near the Galactic Center include Sagittarius, Libra, Scorpius, ...

2010-08-30

Could life once have survived on Mars? Today, neither animal nor plant life from Earth could survive for very long on Mars because at least one key ingredient -- liquid water -- is essentially absent on the red planet's rusty surface. Although ...

2010-08-29 American Scientist

The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun. It can be quite ...

2010-08-28

This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively from space since the ...

2010-08-27 Babak Tafreshi

ven though you may have just read an email claiming Mars will be incredibly bright tonight, the brightest star on the horizon is not Mars. From central Iran on August 24th, the brightest star in this twilight desert skyview is Venus, aka the ...

2010-08-26 Matthew T. Russell

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st ...

2010-08-24

What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster requires not only deep images from telescopes like the Hubble Space Telescope, but detailed computer modeling as well. To start, almost ...

2010-08-23 Alex Cherney

Have you ever seen the Milky Way's glow create shadows? To do so, conditions need to be just right. First and foremost, the sky must be relatively clear of clouds so that the long band of the Milky Way's central disk can be seen. The surroundings ...

2010-08-22

Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder ...

2010-08-21 Robert Arn

Storms on the distant horizon and comet dust raining through the heavens above are combined in this alluring nightscape. The scene was recorded in the early hours of August 13 from the Keota Star Party site on the Pawnee National Grasslands of ...