Heavens

WASHINGTON, Oct. 6 -- Nature creates countless stunning optical phenomena. Some of the most familiar are rainbows, fog bows, coronas, sprites, and mirages, but other, more complex and often more compelling phenomena are also witnessed and imaged, though far less frequently and often under challenging conditions that require great patience. When captured as images, these phenomena also reveal important scientific insights into the properties of light under normal and extreme natural conditions.

SANTA CRUZ, CA--Astrophysicists have detected pulsed gamma-ray emission from the Crab pulsar at energies far beyond what current theoretical models of pulsars can explain.

Atherosclerosis is a major contributor to worldwide mortality and is characterized by narrowing of the arteries due to a thickening of the vessel wall. This restricts blood supply to the tissues and can lead to heart attack or stroke. In many cases, implantation of a stent can successfully be used for revascularization of the obstructed or stenosed arteries to improve blood flow. However, when a regrowth of cells occurs in the inner vessel wall (the intima) or healing of the endothelial cell lining in the vessel lumen is incomplete, the result can be a restenosis, i.e.

Tropical Depression Nalgae weakened rapidly when it made landfall on Hainan Island, China yesterday and NASA's TRMM satellite observed lighter rainfall rates that coincided with its lower intensity. Today, Nalgae's remnants are moving drifting toward Vietnam.

Tropical Depression Nalgae weakened rapidly when it made landfall on Hainan Island, China yesterday and NASA's TRMM satellite observed lighter rainfall rates that coincided with its lower intensity. Today, Nalgae's remnants are moving drifting toward Vietnam.

ANN ARBOR, Mich. -- New evidence supports the theory that comets delivered a significant portion of Earth's oceans, which scientists believe formed about 8 million years after the planet itself.

The findings, which involve a University of Michigan astronomer, are published Oct. 5 online in Nature.

"Life would not exist on Earth without liquid water, and so the questions of how and when the oceans got here is a fundamental one," said U-M astronomy professor Ted Bergin, "It's a big puzzle and these new findings are an important piece."

Supernovas -- stars in the process of exploding -- open a window onto the history of the elements of Earth's periodic table as well as the history of the universe. All of those heavier than oxygen were formed in nuclear reactions that occurred during these explosions.

PROVIDENCE, R.I. [Brown University] -- Ever since the Mariner 10 mission in 1974 snapped the first pictures of Mercury, planetary scientists have been intrigued by smooth plains covering parts of the surface. Some suspected past volcanic activity, but there were no telltale signs like protruding volcanoes. Also, Mercury's northern plains are the same brightness as its cratered highlands, yet different from volcanic deposits on the Moon, which are darker than the highlands.

Leptothorax acervorum ants live all over the Northern hemisphere, but their reproductive strategy depends on habitat. Colonies are polygynous (more than one queen) in the forest of Siberia and central Europe, but functionally monogynous (only one queen reproduces) on sun-exposed slopes in Alaska, Hokkaido and the mountains of central Spain.

Washington, D.C.—Only six months into its Mercury orbit, the tiny MESSENGER spacecraft has shown scientists that Mercury doesn't conform to theory. Its surface material composition differs in important ways from both those of the other terrestrial planets and expectations prior to the MESSENGER mission, calling into question current theories for Mercury's formation. Its magnetic field is unlike any other in the Solar System, and there are huge expanses of volcanic plains surrounding the north polar region of the planet and cover more than 6% of Mercury's surface.

SANTA CRUZ, CA--The Bolshoi supercomputer simulation, the most accurate and detailed large cosmological simulation run to date, gives physicists and astronomers a powerful new tool for understanding such cosmic mysteries as galaxy formation, dark matter, and dark energy.

The simulation traces the evolution of the large-scale structure of the universe, including the evolution and distribution of the dark matter halos in which galaxies coalesced and grew. Initial studies show good agreement between the simulation's predictions and astronomers' observations.

Astronomers from the University Jena have found a stardust belt in extra-solar planetary systems.

The debris discs are remnants of the formation of the planets. This dust is of greatest importance for astronomers, because it helps to draw conclusions about planet formation. There are two debris discs in our solar system, the asteroid belt and the Kuiper belt.

The intricate glowing shells of gas in Holmberg II were created by the energetic lifecycles of many generations of stars. High-mass stars form in dense regions of gas, and later in life expel strong stellar winds that blow away the surrounding material. At the very end of their lives, they explode in as a supernova. Shock waves rip through these less dense regions blowing out and heating the gas, forming the delicate shells we see today.

All observations in astronomy are based on light emitted from stars and galaxies and, according to the general theory of relativity, the light will be affected by gravity. At the same time all interpretations in astronomy are based on the correctness of the theory of relatively, but it has never before been possible to test Einstein's theory of gravity on scales larger than the solar system.

A monster star, known to astronomers as IRAS 17163-3907[1], has a diameter about a thousand times bigger than our Sun. At a distance of about 13 000 light-years from Earth, it is the closest yellow hypergiant found to date and new observations show it shines some 500 000 times more brightly than the Sun[2].

The observations of the star and the discovery of its surrounding shells were made using the VISIR infrared camera on the VLT. The pictures are the first of this object to clearly show the material around it and reveal two almost perfectly spherical shells.