Instead of WIMPS or axions, dark matter may be made of macroscopic objects as small as a few ounces up to the size of a good asteroid, and probably as dense as a neutron star or the nucleus of an atom.
Collisions of heavenly bodies generate almost unimaginable levels of energy. Researchers at Brown University used NASA's ultra-high-speed cannon and computer models to simulate such a collision on Vesta, the second-largest object in the asteroid belt. Their analysis of the images - taken at a million frames per second - shows how Vesta may have gotten the deep grooves that encircle its midsection.
The mystery about a thin, bizarre object in the center of the Milky Way that some astronomers believe to be a hydrogen gas cloud headed toward our galaxy's enormous black hole has been solved by UCLA astronomers.
An international team of astronomers has carried out the most accurate study so far of the cocoon of gas and dust surrounding the GG Tau A system. By combining complementary observations at submillimeter (ALMA and IRAM) wavelengths with those at infrared (VLTI/ESO) wavelengths, the researchers were able to identify the complex dynamics at work in GG Tau.
By using the full power of the Very Large Telescope Interferometer an international team of astronomers has discovered exozodiacal light close to the habitable zones around nine nearby stars. This light is starlight reflected from dust created as the result of collisions between asteroids, and the evaporation of comets. The presence of such large amounts of dust in the inner regions around some stars may pose an obstacle to the direct imaging of Earth-like planets.
The Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago. The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed 'Pandora's Cluster', also known as Abell 2744
Astronomers have long sought to understand exactly how the universe evolved from its earliest history to the cosmos we see around us in the present day. In particular, the way that galaxies form and develop is still a matter for debate. Now a group of researchers have used the collective efforts of the hundreds of thousands of people that volunteer for the Galaxy Zoo project to shed some light on this problem.
Astronomers have detected a streamer of dust and gas flowing from a massive outer disk toward the inner reaches of a binary star system. This never-before-seen feature may be responsible for sustaining a second, smaller disk of planet-forming material that otherwise would have disappeared long ago.
Astronomy and Astrophysics is publishing a special feature of 31 articles describing the data gathered by Planck over 15 months of observations and released by ESA and the Planck Collaboration in March 2013. This series of papers presents the initial scientific results extracted from this first Planck dataset.
Researchers are finding ways to understand some of the mysteries of space without leaving earth. Using high-intensity lasers focused on targets smaller than a pencil's eraser, they conducted experiments to create colliding jets of plasma knotted by plasma filaments and self-generated magnetic fields, reaching pressures a billion times higher than seen on earth.
Thermodiffusion, also called the Soret effect, is a mechanism by which an imposed temperature difference establishes a concentration difference within a mixture. Two recent studies provide a better understanding of such effects. They build on recent experimental results from the Influence Vibration on Diffusion in Liquids research project performed on the International Space Station under microgravity to avoid motion in the liquids.
NASA is seeking proposals to develop and manufacture ultra-lightweight materials for aerospace vehicles and structures of the future. Proposals will demonstrate lower-mass alternatives to honeycomb or foam cores currently used in composite sandwich structures.
Scientists have identified a key phenomenon in the triggering of solar flares. Using satellite data and models, the scientists were able to monitor the evolution of the solar magnetic field in a region with eruptive behavior.