Heavens

Though it was once believed that all asteroids are giant pieces of solid rock, later hypotheses have it that some are actually a collection of small gravel-sized rocks, held together by gravity. If one of these "rubble piles" spins fast enough, it's speculated that pieces could separate from it through centrifugal force and form a second collection ― in effect, a second asteroid.

Beyond the orbit of Neptune reside countless icy rocks known as trans-Neptunian objects (TNOs). One of the biggest, Pluto, is classified as a dwarf planet. The region also supplies us with comets such as famous Comet Halley. Most TNOs are small and receive little sunlight, making them faint and difficult to spot.

Men aged 55 to 74 years who have low baseline blood levels of prostate specific antigen (PSA) are not likely to benefit from further screening and treatment. That is the conclusion of a new study published early online in Cancer, a peer-reviewed journal of the American Cancer Society. The aim of the study is to help physicians and patients weigh the pros and cons of prostate cancer screening and early detection.

ALBUQUERQUE, NM — Two amateur astronomers who independently observed and videotaped an asteroid striking the giant planet Jupiter on June 3 have opened the possibility, in effect, of a giant research lab in space for planetary scientists.

According to a paper by in Astrophysical Journal Letters, the asteroid was eight to 13 meters in diameter and packed a punch equivalent to a 250- to 1,000-kiloton nuclear bomb — smaller than the violent airburst that decimated trees for 40 kilometers around Tunguska in central Siberia 100 years ago, but similar in its effects.

The San Diego Supercomputer Center and Cooperative Association for Internet Data Analysis (CAIDA) at the University of California, San Diego, in a collaboration with researchers from Universitat de Barcelona in Spain and the University of Cyprus, have created the first geometric "atlas" of the Internet as part of a project to prevent our most ubiquitous form of communication from collapsing within the next decade or so.

The existence of Dark Matter particles in the Sun's interior seems inevitable to some in physics, despite dark matter never having been observed there or anywhere else. Further, they say once gravitationally captured by the Sun, these particles tend to accumulate in its core.

A group of international astronomers in the UK, France and the USA, led by the University of Leicester, have found proof to confirm the distance and brightness of the most extreme ultra-luminous X-ray source, which may herald a new type of Black Hole.

As children in Western cultures grow, they learn to place numbers on a mental number line, with smaller numbers to the left and spaced further apart than the larger numbers on the right. Then the number line changes to become more linear, with small and large numbers the same distance apart. Children whose number line has made this change are better at remembering numbers, according to a new study published in Psychological Science, a journal of the Association for Psychological Science.

In the midst of a difficult fire season in many parts of the world, the United Nations' (UN) Food and Agriculture Organization has launched a new online fire detection system that will help firefighters and natural hazards managers improve response time and resource management.

Volcanoes display the awesome power of Nature like few other events. Earlier this year, ash from an Icelandic volcano disrupted air travel throughout much of northern Europe. Yet this recent eruption pales next to the fury of Jupiter's moon Io, the most volcanic body in our solar system.

Scientists from the University of California, San Diego School of Medicine have identified dendritic antigen-presenting cells in zebrafish, opening the possibility that the tiny fish could become a new model for studying the complexities of the human immune system.

The study, reported in the online edition of the Proceedings of the National Academy of Sciences, was headed by David Traver, an associate professor in UCSD's Department of Cellular and Molecular Medicine, with colleagues in UCSD's Division of Biological Sciences and at the Brazilian National Cancer Institute.

The likelihood that the treatment of a middle ear infection will fail is slightly higher for a child who is given a shorter course of antibiotics, according to a new Cochrane Systematic Review. The results are conclusive, but the researchers say there are other factors that must be considered when the drugs are prescribed.

Volcanoes display the awesome power of Nature like few other events. Earlier this year, ash from an Icelandic volcano disrupted air travel throughout much of northern Europe. Yet this recent eruption pales next to the fury of Jupiter's moon Io, the most volcanic body in our solar system.

Employees who have control over the design and layout of their workspace are not only happier and healthier — they're also up to 32% more productive, according to new research from the University of Exeter in the UK.