الأحد، 15 سبتمبر 2013

ScienceDaily: Top News

ScienceDaily: Top News


Earth's wobble 'fixes' dinner for marine organisms

Posted: 13 Sep 2013 04:51 PM PDT

The cyclic wobble of the Earth on its axis controls the production of a nutrient essential to the health of the ocean, according to a new study. The discovery of factors that control this nutrient, known as "fixed" nitrogen, gives researchers insight into how the ocean regulates its own life-support system, which in turn affects the Earth's climate and the size of marine fisheries.

Fireballs in Jupiter's atmosphere observed by amateur astronomers

Posted: 13 Sep 2013 04:50 PM PDT

The solar system is crowded with small objects like asteroids and comets. Most have stable orbits which keep them out of harm's way, but a small proportion of them are in orbits that risk them colliding with planets.

Assumptions about origins of life challenged

Posted: 13 Sep 2013 03:58 PM PDT

Before there was life on Earth, there were molecules. A primordial soup. At some point a few specialized molecules began replicating. This self-replication, scientists agree, kick-started a biochemical process that would lead to the first organisms. But exactly how that happened -- how those molecules began replicating -- has been one of science's enduring mysteries. Biochemists now offer an intriguing new view on how life began.

Spider silk coated with carbon nanotubes has multiple surprising uses

Posted: 13 Sep 2013 03:58 PM PDT

Physicists have discovered that simple methods can result in surprising and environmentally friendly high-tech outcomes during their experiments with spider silk and carbon nanotubes. Spider silk coated with nanotubes can act as a humidity sensor, a strain sensor, an actuator (a device that acts as an artificial muscle, for lifting weights and more) and as an electrical wire, according to researchers.

Balloon-borne astronomy experiment X-Calibur racing to hit wind window

Posted: 13 Sep 2013 03:58 PM PDT

In a few days, a balloon-borne telescope sensitive to the polarization of high-energy "hard" X-rays will ascend to the edge of the atmosphere above Fort Sumner, N.M. Once aloft, the telescope will stare at black holes, neutron stars and other exotic astronomical objects that shine brightly in the X-ray part of the spectrum in order to learn about their nature and structure. After years of preparation, the X-Calibur team is racing to get the experiment mission-ready in time for the stratospheric wind event they hope to ride.

Speedy chemical reaction captured in mid-stride

Posted: 13 Sep 2013 03:58 PM PDT

In synthetic chemistry, making the best possible use of the needed ingredients is key to optimizing high-quality production at the lowest possible cost. The element rhodium is a powerful catalyst — a driver of chemical reactions — but is also one of the rarest and most expensive. In addition to its common use in vehicle catalytic converters, rhodium is also used in combination with other metals to efficiently drive a wide range of useful chemical reactions.

Catastrophic collapse of ice lake created Aram Chaos on Mars

Posted: 13 Sep 2013 09:41 AM PDT

Aram Chaos, the lumpy, bumpy floor of an ancient impact crater on Mars, formed as a result of catastrophic melting and outflow of a buried ice lake. A new study combines observations from satellite photos of the 280 kilometer wide and four kilometer deep crater plus models of the ice melting process and resulting catastrophic outflow.

Get ready for Rosetta's wake-up call with activity schedule for target comet

Posted: 13 Sep 2013 09:41 AM PDT

After a journey of almost ten years, the Rosetta mission has just a few months left to wait before beginning its rendezvous with a time capsule. Comet 67P/Churymov-Gerasimenko is a dirty snowball of ice and dust that preserves material from the formation of the Solar System 4.5 billion years ago.

Changes in Saturn's Moon Titan’s surface brightness point to cryovolcanism

Posted: 13 Sep 2013 09:41 AM PDT

Changes in surface brightness on Titan observed over four years by NASA's Cassini spacecraft have added to evidence that cryovolcanism is active on Saturn's largest Moon. Astronomers compared many volcanic-like features, such as flows, calderas and craters, with similar geological features found on Earth to study the possibility of cryovolcanic activity within regions observed close to Titan's equator.

'Grassroots action' in livestock feeding to help curb global climate change

Posted: 13 Sep 2013 07:18 AM PDT

Scientists offer new evidence that a potent chemical mechanism operating in the roots of a tropical grass used for livestock feed has enormous potential to reduce greenhouse gas emissions.

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