Astronomy Picture Of the Day (APOD)Apogee Moon, Perigee Moon
Why don't these pieces fit? This third quarter Moon (left) and first quarter Moon were both photographed during the last lunar cycle or lunation with the same telescope and camera. But, simply combining the pictures into one sharp, full surface view would clearly be a problem.
NGC 281: Cluster, Clouds, and Globules
NGC 281 is a busy workshop of star formation. Prominent features include a small open cluster of stars, a diffuse red-glowing emission nebula, large lanes of obscuring gas and dust, and dense knots of dust and gas in which stars may still be forming.
Old Planetary Dust Disks Found by SST
Why are some older stars surrounded by dust? Observations from the Spitzer Space Telescope by a team led by George Rieke (U. Arizona) were expected to show that young stars, on the order of one million years old, have large dust disks, while relatively older stars, between 10 and 100 million years old, have none.
Southern Saturn from Cassini
What happens to Saturn's pervasive clouds at its South Pole? Visible in the above image of Saturn are bright bands, dark belts and a dark spot right over the South Pole. The above...
IC 418: The Spirograph Nebula
What is creating the strange texture of IC 418? Dubbed the Spirograph Nebula for its resemblance to drawings from a cyclical drawing tool, planetary nebula IC 418 shows patterns that are not well understood. Perhaps they are related to chaotic winds from the variable central star, which changes brightness unpredictably in just a few hours.
The Bubbling Cauldron of NGC 3079
Edge-on spiral galaxy NGC 3079 is a mere 50 million light-years away toward the constellation Ursa Major. Shown in this stunning false-color Hubble Space Telescope image, the galaxy's disk - composed of spectacular star clusters in winding spiral arms and dramatic dark lanes of dust - spans some 70,000 light-years.
Is it magic? On a rare foggy night, mysterious laser beams seem to play across the MAGIC telescope at Roque de los Muchachos on the Canary Island of La Palma. The lasers are actually part of a system designed to automatically adjust the focusing of the inovative, seventeen meter wide, multi-mirrored instrument.
Glimpse of a Globular Star Cluster
Not a glimpse of this cluster of stars can be seen in the inset visible light image (lower right). Still, the infrared view from the Spitzer Space Telescope reveals a massive globular star cluster of about 300,000 suns in an apparently empty region of sky in the constellation Aquila.
Contrail Clutter over Georgia
Artificial clouds made by humans may become so common they change the Earth's climate. The long thin cloud streaks that dominate the above satellite photograph of Georgia are contrails, cirrus clouds created by airplanes. The exhaust of an airplane engine can create a contrail by saturating the surrounding air with extra moisture.
M3: Inconstant Star Cluster
Star clusters appear constant because photographs of them are frozen in time. In reality, though, cluster stars swarm the center and frequently fluctuate in brightness. Although the time it takes for stars to cross...