Our universe is filled with galaxies. Galaxies -- huge conglomerations of stars, gas, dust -- and mysterious dark matter are the basic building blocks of the large-scale universe. Although distant galaxies move away from each other as the ...
What became of the first stars? No known stars appear to be composed of truly primordial gas -- all of the stars around us have too many heavy elements. Our own Sun is thought to be a third generation star, with many second-generation stars ...
At 500,000 kilometers per hour, a supernova shockwave plows through interstellar space. This shockwave is known as the Pencil Nebula, or NGC 2736, and is part of the Vela supernova remnant, an expanding shell of a star that exploded about 11,000 ...
Rhea is the second largest moon of Saturn, behind Titan, and the largest without an atmosphere. It is composed mostly of water ice, but has a small rocky core. Rhea's rotation and orbit are locked together (just like Earth's Moon) so that one ...
How did spiral galaxy ESO 510-13 get bent out of shape? The disks of many spirals are thin and flat, but not solid. Spiral disks are loose conglomerations of billions of stars and diffuse gas all gravitationally orbiting a galaxy center. A flat ...
Anticipating the celestial shadow play of a solar eclipse, sky gazers across Germany watched the Sun rise on May 31. In Bonn, astrophotographer Thilo Kranz had set up his small refractor telescope and camera on the Kennedy Bridge across the Rhein ...
If the Moon's apparent diameter is not quite large enough to cover the Sun during a solar eclipse, an annular eclipse can be the result -- a spectacle of silhouetted Moon surrounded by a solar "ring of fire". Just such a view was possible for ...
The Sun and Moon rose together over much of Europe on the morning of May 31st with the first solar eclipse of 2003 already in progress. And while sightings of the full annular phase of the eclipse were restricted to far northern regions, early ...
What's behind the Moon? Each month, our Moon passes in front of -- and outshines -- many an interesting star field. Exceptions occur during a new Moon and during a total eclipse. In the background of a new Moon is usually the Sun, an even ...
Fogs of clouds and dust covered parts of southern Mars during last Martian winter. Giant volcanoes, such as Ascraeus Mons, the central circular feature near the top of the image, were surrounded by large water clouds. Slightly southwest, ...