Astronomy Picture Of the Day (APOD)Starlight Reflections
Wisps of dust fill the space between the stars. This dust is usually invisible, subtly acting to dim the light of more distant stars. Sometimes this dust is thick and prominent as dark patches on otherwise bright emission nebulae. Other times this dust may show itself by reflecting the light of bright, nearby stars.
The Sun Changes
Our Sun changes every day. This recent picture was taken in a very specific red color called Hydrogen-Alpha. Dark spots that might appear on the image are usually sunspots, dark magnetic depressions that are slightly cooler than the rest of the Sun's surface.
Stars from Eagle's EGGs
Newborn stars are forming in the Eagle Nebula. This image, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars.
NGC 604: Giant Stellar Nursery
Scattered within this cavernous nebula, cataloged as NGC 604, are over 200 newly formed hot, massive, stars. At 1,500 light-years across, this expansive cloud of interstellar gas and dust is effectively a giant stellar nursery located some three million light-years distant in the spiral galaxy, M33.
Hyakutake: Comet Atmosphere
The atmosphere of a comet comes and goes. Approaching the sun, it swells as material from the icy cometary nucleus is warmed and evaporated by increasing sunlight. Immense but tenuous and fleeting, the inner atmosphere or inner "coma" of comet Hyakutake is seen in this false color picture.
Quasar in an Elliptical Galaxy
Where do quasars live? Quasars are the brightest objects in the universe, so bright they can be seen from across the universe. Observations continue to show that most quasars are surrounded by a relatively faint nebulous patch. Astronomers are trying to identify the nature of these patches.
Nabta: Older than Stonehenge
In the Sahara Desert in Egypt lie the oldest known astronomically aligned stones in the world: Nabta. Over one thousand years before the creation of Stonehenge, local herders built a stone circle and other structures on the shoreline of a lake that has long since dried up.
Return To Cydonia
Yesterday the Mars Global Surveyor project released a new close-up image of a portion of the Cydonia region on Mars. This cropped and processed version shows an area about 2 miles wide (the full...
A Face On Mars
This image, showing what looks to be a human face (above center) and other features of the Cydonia region on the Martian surface, was produced using data from NASA's Viking 1 orbiter in 1976.
The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as a lovely and tantalizing grouping of stars in the constellation of Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight.