Science & TechnologyS


Sun

Bright Points on the Quiet Sun

Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
Astronomy Picture of the Day
Fri, 16 Apr 2010 17:03 UTC
Bright Points on the Quiet Sun
© J. Sanchez Almeida (IAC), et al.Bright Points on the Quiet Sun
Up close, the solar surface is a striking patch work of granules in this very high resolution picture of the quiet Sun. Caused by convection, the granules are hot, rising columns of plasma edged by dark lanes of cooler, descending plasma. But the high-resolution view reveals that the dark lanes are dotted with many small, contrasting bright points. Constantly present on the solar surface, the bright points do not seem to be related to sunspots that come and go with the magnetic solar cycle. Nonetheless, the bright points are regions of concentrated magnetic fields and are bright because the magnetic pressure opens a window to hotter deeper layers below the photosphere.
Read More...
Info

Scanning for Asteroids and Comets by WISE

Paul Adams
Vizworld
Fri, 28 May 2010 16:52 UTC

This movie shows asteroids observed so far by NASA's Wide-field Infrared Survey Explorer, or WISE. As WISE scans the sky from its polar orbit, more and more asteroids and comets are caught in its infrared vision. The mission has surveyed about three-fourths of the sky; however, data for only about 50 percent of the sky has been processed for asteroids and comets at this time.

The white dots show asteroids observed by WISE - most of these are in the Main Belt between Mars and Jupiter, and some, the Trojans, orbit in front of, or behind, Jupiter. The red dots represent newfound near-Earth objects, which are asteroids and comets with orbits that come relatively close to Earth's path around the sun. The green dots are previously known near-Earth objects observed by WISE. The yellow squares show all comets seen by WISE so far.

As of May 24, 2010, WISE has seen more than 60,000 asteroids. It has observed more than 70 comets, 12 of which are new, and about 200 near-Earth objects, more than 50 of which are new.

Credit: NASA/JPL-Caltech/ULCA/JHU
Read More...
Info

The Earth's Secrets, Hidden in the Skies

Daniel N. Baker
New York Times
Thu, 27 May 2010 16:37 UTC
One of the greatest advances in space technology has been the military's Global Positioning System satellites, which provide remarkably accurate navigation information for everything from smart phones and cars to pet collars.

But the navigational data is only one part of the program's mission. The Nuclear Detonation Detection System, an array of sensors also on board the satellites, watches the world for nuclear explosions. In the process, it collects mounds of environmental data which, in the hands of climate scientists, could add greatly to our understanding of global warming.

Unlike the G.P.S. information, however, much of the detection system data is hidden behind bureaucratic walls by national security agencies, which treat it as classified, even though it isn't, and even though there's no compelling national security reason to do so.

The history of the G.P.S. system shows the impact satellite data can have on commercial and scientific progress. Since it was first made publicly available in the 1980s, G.P.S. has revolutionized industries from telecommunications to agriculture. Estimates place its economic value in the tens to hundreds of billions of dollars each year. And that's not counting its impact on everyday activities like hiking, boating and golf.
Read More...
Telescope

Ancient view of the night sky


New Scientist
Fri, 28 May 2010 11:19 UTC
Celestial scenes like this one of the Milky Way are getting rarer by the day. Light pollution overwhelms views of our galaxy for two-thirds of the population of the US and the majority of Europeans. But some "optically clean" oases where we can look at the stars unhindered do remain, called "Dark Sky Parks". This site in Canyonlands National Park in Utah is near one of them.

Image
© Bret Webster
The sky here appears much as it would have done 4000 years ago, when artists in the so-called Archaic civilisation are thought to have painted the ghost-like figures on the canyon walls. No other cultural artefacts have been found, suggesting the site, known as the Great Gallery, was not used for everyday living but for special religious ceremonies.
Read More...
Meteor

Did a Comet strike Neptune 200 years ago?

Eric Hand
Nature
Fri, 28 May 2010 12:26 UTC
Image
© NASA/JPLAn abundance of carbon monoxide in Neptune's atmosphere could be the result of a comet smash
Did a large, icy comet smash into Neptune two centuries ago? That's the picture that is emerging from the latest measurements of gases in the atmosphere of the giant blue planet.

At a meeting this week of the American Astronomical Society in Miami, Florida, Paul Hartogh, project scientist for the Herschel mission, the European Space Agency's infrared observatory satellite, described the mission's first results for the Solar System. These include measurements of abnormally high levels of carbon monoxide in Neptune's stratosphere - a possible trace of a comet impact.

Emmanuel Lellouch, an astronomer at the Paris Observatory, first published the idea five years ago, on the basis of far less certain measurements made by a 30-metre radio telescope on the mountain Pico Veleta in Spain[1]. "We are becoming more confident," says Lellouch, who is a co-author with Hartogh on a forthcoming paper concerning the Herschel results in the journal Astronomy & Astrophysics.
Read More...
Info

DNA replication... without life

Kate McAlpine
New Scientist
Thu, 27 May 2010 12:10 UTC
Image
© University of Delaware/JGI/DOEProviding a perfect setting for life to replicate
The precursor of life may have learned how to copy itself thanks to simple convection at the bottom of the ocean. Lab experiments reveal how DNA replication could have occurred in tiny pores around undersea vents.

One of the initial steps towards life was the first molecule capable of copying itself. In the open ocean of early Earth, strands of DNA and loose nucleotides would have been too diluted for replication to occur. So how did they do it?

Inside many undersea hydrothermal vents, magnesium-rich rocks react with sea water. Such reactions create a heat source that could drive miniature convection currents in nearby pores in the rock, claim Christof Mast and Dieter Braun of Ludwig Maximilian University of Munich, Germany. They propose that such convection could concentrate nucleotides, strands of DNA, and polymerase, providing a setting that would promote replication.

Sea water inside pores on or near a vent's chimney may undergo thermal convection because the water at the wall of the pore closest to the vent's heat source would be warmer than the water near the furthermost wall, say Mast and Braun. If the pore contained strands of DNA, nucleotides, and polymerase they would ride upward in the warm current. The DNA strands would also be "unzipped" in the heat, splitting into two strands that each serve as templates for eventual replication.

All these components would then tend to shift away from the rising warmer region. In air, particles typically shift into a colder current because they are more likely to be pushed away by warmer, more energetic molecules than those on the cooler, calmer side. The researchers reckon a similar process would occur in the fluid in the vents.
Read More...
Sherlock

Scientists Announce New Horned Dinosaur


PhysOrg
Fri, 28 May 2010 11:10 UTC
Image
© Luis ReyMedusaceratops
Michael J. Ryan, Ph.D., a scientist at The Cleveland Museum of Natural History, has announced the discovery of a new horned dinosaur, Medusaceratops lokii. Approximately 20 feet long and weighing more than 2 tons, the newly identified plant-eating dinosaur lived nearly 78 million years ago during the Late Cretaceous period in what is now Montana. Its identification marks the discovery of a new genus of horned dinosaur.

Ryan, curator and head of Vertebrate Paleontology at the Museum, published his findings on the new genus in the book, New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium, available from Indiana University Press. Ryan was the book's lead editor.

Medusaceratops belongs to the Chasmosaurinae subfamily of the horned dinosaur family Ceratopsidae. The other subfamily is Centrosaurinae. The specimen is the first Campanian-aged chasmosaurine-ceratopsid found in Montana. It is also the oldest known Chasmosaurine ceratopsid.

The new dinosaur was discovered in a bonebed on private land located along the Milk River in North Central Montana. Fossilized bones from the site were acquired by Canada Fossil, Inc., of Calgary, Alberta, in the mid-1990s.
Read More...
Info

Snails on speed shed light on how patholgical memories form in addicts

Jessica Hamzelou
New Scientist
Fri, 28 May 2010 12:04 UTC
Image
© Colin Milkins/GettyThis place reminds me of something
Pond snails make unlikely speed freaks. But dosing the gastropods on methamphetamine is helping us understand how certain "pathological memories" form in human addicts.

Meth users develop long-term memories of their highs, which is why the sight of places and people connected with a high can cause recovering addicts to relapse into taking the drug. "It's hard to get rid of those memories in addicts," says Barbara Sorg at Washington State University in Pullman. So potent is meth's effect on memory that, in low doses, the drug can be used as a "cognitive enhancer" in kids with attention-deficit hyperactivity disorder.

To probe the drug's effect on memory, Sorg's team placed pond snails in two pools of low-oxygen water, one of which was laced with meth. In low-oxygen conditions snails will surface and use their breathing tubes to access more oxygen. By poking the snails, Sorg's team trained them to associate using the tubes with an unpleasant experience, and so keep them shut. Only the snails on speed remembered their training the following morning, and in a separate experiment it took longer for them to "unlearn" the memory.
Read More...
Heart

Arizona man is first to take artificial heart home

Andy Coghlan
New Scientist
Thu, 27 May 2010 11:57 UTC
Charles Okeke, a 43-year-old father of three from Phoenix, Arizona, is the first person to leave hospital with a completely artificial heart. Since 3 May he has been home with his family, thanks to a backpack-sized device that is powerful enough to keep his artificial heart pumping while he awaits a donor heart. How does the heart work and what's next for synthetic organs? New Scientist provides some answers.

Read More...
Sun

Cosmic hit-and-runs create failed stars

Rachel Courtland
New Scientist
Thu, 27 May 2010 11:53 UTC
Image
© Ingo Thies, Pavel Kroupai and Simon P. Goodwin et alA snapshot of a circumstellar disc around a Sun-type star being perturbed by a close star-star encounter.
It's hit-and-run on a cosmic scale. Close encounters between swerving young stars might help spawn the brown dwarfs riddling the Milky Way.

Brown dwarfs are balls of gas whose mass is generally dozens of times that of Jupiter. Like stars, brown dwarfs are capable of fusing hydrogen atoms, but they are too lightweight to sustain the process.

The origin of these failed stars is a mystery. Brown dwarfs might form like their larger cousins, collapsing directly from turbulent gas clouds, or they might form in a similar way to planets, condensing out of the discs of gas girdling young stars.

Simulations had shown that instabilities in the disc of gas around an isolated young star can trigger the formation of brown dwarfs. Now Ingo Thies and Pavel Kroupa of the University of Bonn in Germany, and colleagues, have shown that the process can also take place in a more commonplace scenario, involving a crowded cluster of newborn stars.

In new simulations, the team found that young stars that zoom close enough to their siblings can destabilise the surrounding gas discs, allowing denser areas to collapse rapidly and form brown dwarf-sized objects.
Read More...