Earth Weather / Space Weather

Physics for Lunch, Anyone?

By: Susie77, 6:18 PM GMT on November 30, 2010

An interesting article from Live Science



Dawn of the Universe Recreated

By LiveScience Staff

posted: 30 November 2010 09:38 am ET


Just weeks after the world's largest particle accelerator began smashing together heavy lead ions to create little Big Bangs, the experiment has produced a primordial state of matter akin to what existed at the dawn of the universe.

The Large Hadron Collider (LHC), a 17-mile-long (27 kilometer) underground ring run by the European Organization for Nuclear Research (CERN) near Geneva, began colliding lead ions together Nov. 8. These atomic nuclei contain 82 protons, and are much heavier than the lone protons the accelerator was previously colliding.

Now two experiments at the LHC – called ATLAS and CMS, respectively – have reported a phenomenon called "jet quenching" that scientists say could reveal secrets about the nature of matter and the evolution of the universe.

Jet quenching

After two ions crash into each other, detectors measure jets of particles that emerge from the high-energy collision. Jets are formed as the basic constituents of nuclear matter, called quarks and gluons, fly away from the collision point.

In proton collisions, jets usually appear in pairs, emerging back to back. However, in the tumultuous conditions created by heavy ion collisions such as those made by lead nuclei, the jets interact with a hot dense medium created when temperatures are so high that the basic constituents of matter break apart.

This leads to a characteristic signal, known as jet quenching, in which the energy of the jets can be severely degraded, signaling interactions with the medium more intense than ever seen before.

"ATLAS is the first experiment to report direct observation of jet quenching," said ATLAS spokesperson Fabiola Gianotti in a statement. "The excellent capabilities of ATLAS to determine jet energies enabled us to observe a striking imbalance in energies of pairs of jets, where one jet is almost completely absorbed by the medium."

Probing very early universe

Jet quenching is a powerful tool for studying nature, especially the behavior of the medium of broken-down particles, called quark-gluon plasma. This plasma is created when super-high temperatures break apart protons into their constituent quarks and gluons. The quarks and gluons then float around in a kind of primordial soup that resembles the universe shortly after the Big Bang.

"It is truly amazing to be looking, albeit on a microscopic scale, at the conditions and state of matter that existed at the dawn of time," said CMS spokesperson Guido Tonelli. "Since the very first days of lead-ion collisions, the quenching of jets appeared in our data while other striking features, like the observation of Z particles, never seen before in heavy-ion collisions, are under investigation. The challenge is now to put together all possible studies that could lead us to a much better understanding of the properties of this new, extraordinary state of matter." (A Z particle is nearly identical to a massless photon yet is very massive.)

The quark-gluon plasma was created for the first time ever at a smaller particle accelerator called the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Batavia, Ill. That finding was announced in February 2010.

The ATLAS and CMS measurements offer a new possibility to use jets, which interact with the primordial soup, to probe this unique state of matter, scientists said. Future jet quenching and other measurements from the LHC experiments will provide powerful insight into the properties of the primordial plasma and the interactions among its quarks and gluons, they said.

Preliminary results from the experiments will be presented at a seminar on Dec. 2 at CERN.

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Tantalizing Hints About Extraterrestrial Life from NASA!

By: Susie77, 11:25 PM GMT on November 29, 2010

NASA SETS NEWS CONFERENCE ON ASTROBIOLOGY DISCOVERY; SCIENCE JOURNAL HAS EMBARGOED DETAILS UNTIL 2 P.M. EST ON DEC. 2

WASHINGTON -- NASA will hold a news conference at 2 p.m. EST on
Thursday, Dec. 2, to discuss an astrobiology finding that will impact
the search for evidence of extraterrestrial life. Astrobiology is the
study of the origin, evolution, distribution and future of life in
the universe.

The news conference will be held at the NASA Headquarters auditorium
at 300 E St. SW, in Washington. It will be broadcast live on NASA
Television and streamed on the agency's website at
http://www.nasa.gov.

Participants are:
- Mary Voytek, director, Astrobiology Program, NASA Headquarters,
Washington
- Felisa Wolfe-Simon, NASA astrobiology research fellow, U.S.
Geological Survey, Menlo Park, Calif.
- Pamela Conrad, astrobiologist, NASA's Goddard Space Flight
Center, Greenbelt, Md.
- Steven Benner, distinguished fellow, Foundation for Applied
Molecular Evolution, Gainesville, Fla.
- James Elser, professor, Arizona State University, Tempe

Media representatives may attend the conference or ask questions by
phone or from participating NASA locations. To obtain dial-in
information, journalists must send their name, affiliation and
telephone number to Steve Cole at stephen.e.cole@nasa.gov or call
202-358-0918 by noon Dec. 2.

For NASA TV streaming video and downlink information, visit:



http://www.nasa.gov/ntv

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Earth at Night

By: Susie77, 10:18 PM GMT on November 23, 2010

Astronaut shares amazing photos of our planet taken from the International Space Station.

Earth at Night: Astronaut Shares Dazzling Photos From Space Station

One example -- The aurora, with the lights of London and Paris:

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Snowstorm in Space?

By: Susie77, 10:01 PM GMT on November 19, 2010

From: NASA Science


Comet Snowstorm Engulfs Hartley 2

Nov. 18, 2010: NASA has just issued a travel advisory for spacecraft: Watch out for Comet Hartley 2, it is experiencing a significant winter snowstorm.

Deep Impact photographed the unexpected tempest when it flew past the comet's nucleus on Nov. 4th at a distance of only 700 km (435 miles). At first, researchers only noticed the comet's hyperactive jets. The icy nucleus is studded with them, flamboyantly spewing carbon dioxide from dozens of sites. A closer look revealed an even greater marvel, however. The space around the comet's core is glistening with chunks of ice and snow, some of them possibly as large as a basketball.

Comet Snowstorm (snowstorm, 550px)
This contrast-enhanced image obtained during Deep Impact's Nov. 4th flyby of Comet Hartley 2 reveals a cloud of icy particles surrounding the comet's active nucleus.



"We've never seen anything like this before," says University of Maryland professor Mike A'Hearn, principal investigator of Deep Impact's EPOXI mission. "It really took us by surprise."

Before the flyby of Hartley 2, international spacecraft visited four other comet cores—Halley, Borrelly, Wild 2, and Tempel 1. None was surrounded by "comet snow." Tempel 1 is particularly telling because Deep Impact itself performed the flyby. The very same high resolution, high dynamic range cameras that recorded snow-chunks swirling around Hartley 2 did not detect anything similar around Tempel 1.

"This is a genuinely new phenomenon," says science team member Jessica Sunshine of the University of Maryland. "Comet Hartley 2 is not like the other comets we've visited."

The 'snowstorm' occupies a roughly-spherical volume centered on Hartley 2's spinning nucleus. The dumbbell-shaped nucleus, measuring only 2 km from end to end, is tiny compared to the surrounding swarm. "The ice cloud is a few tens of kilometers wide--and possibly much larger than that," says A'Hearn. "We still don't know for sure how big it is."

Data collected by Deep Impact's onboard infrared spectrometer show without a doubt that the particles are made of frozen H2O, i.e., ice. Chunks consist of micron-sized ice grains loosely stuck together in clumps a few centimeters to a few tens of centimeters wide.
Comet Snowstorm (spectra, 550px)

"If you held one in your hand you could easily crush it," says Sunshine. "These comet snowballs are very fragile, similar in density and fluffiness to high-mountain snow on Earth."

Even a fluffy snowball can cause problems, however, if it hits you at 12 km/s (27,000 mph). That's how fast the Deep Impact probe was screaming past the comet’s nucleus. An impact with one of Hartley 2's icy chunks could have damaged the spacecraft and sent it tumbling, unable to point antennas toward Earth to transmit data or ask for help. Mission controllers might never have known what went wrong.

"Fortunately, we were out of harm's way," notes A'Hearn. "The snow cloud does not appear to extend out to our encounter distance of 700 km. Sunlight sublimates the icy chunks before they can get that far away from the nucleus."

The source of the comet-snow may be the very same garish jets that first caught everyone's eye.

The process begins with dry ice in the comet's crust. Dry ice is solid CO2, one of Hartley 2's more abundant substances. When heat from the sun reaches a pocket of dry ice—poof!—it instantly transforms from solid to vapor, forming a jet wherever local topography happens to collimate the outrushing gas. Apparently, these CO2 jets are carrying chunks of snowy water ice along for the ride.

Because the snow is driven by jets, "it's snowing up, not down," notes science team member Peter Schultz of Brown University.

Ironically, flying by Hartley 2 might be more dangerous than actually landing on it. The icy chunks are moving away from the comet’s surface at only a few m/s (5 to 10 mph). A probe that matched velocity with the comet's nucleus in preparation for landing wouldn't find the drifting snowballs very dangerous at all--but a high-speed flyby is another matter. This is something planners of future missions to active comets like Hartley 2 will surely take into account.

Comet snowstorms could be just the first of many discoveries to come. A’Hearn and Sunshine say the research team is only beginning to analyze gigabytes of data beamed back from the encounter, and new results could be only weeks or months away.

Stay tuned for updates from Comet Hartley 2.

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Leonid Meteor Shower

By: Susie77, 12:40 PM GMT on November 17, 2010

From: Star Date


This year, the Leonid meteor shower best viewing will be in the two to three hours before dawn on November 17 and 18, according to the editors of StarDate magazine.

There is always some uncertainty in the number of meteors the Leonid shower will produce, but viewers should expect to see at least 20 meteors per hour if they have clear skies. The nearly full Moon will set several hours before dawn, and therefore not wash out any meteors in the hours immediately before dawn.

Leonid meteors appear to fall from the constellation Leo, the lion, but they are not associated with it. They are leftover debris from comet Tempel-Tuttle. As the comet orbits the Sun, it leaves a trail of debris. The Leonids meteors recur each year when Earth passes through the comet’s debris trail.

Each time comet Tempel-Tuttle gets closest to the Sun in its orbit, called "perihelion," it sheds a significant amount of material. This creates clumps along its orbit. If Earth passes through one of these clumps this year, viewers could see hundreds of meteors per hour at the shower's peak. If Earth simply passes through the "normal" part of the comet's debris trail, the number of meteors visible will be much lower.

For your best view, get away from city lights. Look for state or city parks or other safe, dark sites. Lie on a blanket or reclining chair to get a full-sky view. If you can see all of the stars in the Little Dipper, you have good dark-adapted vision.

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We Can Finally Meet Our Evil Twins!

By: Susie77, 7:11 PM GMT on November 16, 2010

(I wonder if mine has a goatee?)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CERN scientists eye parallel universe breakthrough

Credit: Reuters/NASA/Handout

By Robert Evans

GENEVA | Wed Oct 20, 2010 11:21am EDT

GENEVA (Reuters) - Physicists probing the origins of the cosmos hope that next year they will turn up the first proofs of the existence of concepts long dear to science-fiction writers such as hidden worlds and extra dimensions.

And as their Large Hadron Collider (LHC) at CERN near Geneva moves into high gear, they are talking increasingly of the "New Physics" on the horizon that could totally change current views of the universe and how it works.

"Parallel universes, unknown forms of matter, extra dimensions... These are not the stuff of cheap science fiction but very concrete physics theories that scientists are trying to confirm with the LHC and other experiments."

This was how the "ideas" men and women in the international research center's Theory Group, which mulls over what could be out there beyond the reach of any telescope, put it in CERN's staff-targeted Bulletin this month.

As particles are collided in the vast underground LHC complex at increasingly high energies, what the Bulletin article referred to informally as the "universe's extra bits" -- if they do exist as predicted -- should be brought into computerized, if ephemeral, view, the theorists say.

Optimism among the hundreds of scientists working at CERN -- in the foothills of the Jura mountains along the border of France and Switzerland -- has grown as the initially troubled $10 billion experiment hit its targets this year.

PROTON COLLISIONS

By mid-October, Director-General Rolf Heuer told staff last weekend, protons were being collided along the 27-km (16.8 mile) subterranean ring at the rate of 5 million a second -- two weeks earlier than the target date for that total.

By next year, collisions will be occurring -- if all continues to go well -- at a rate producing what physicists call one "inverse femtobarn," best described as a colossal amount, of information for analysts to ponder.

The head-on collisions, at all but the speed of light, recreate what happened a tiny fraction of a second after the primeval "Big Bang" 13.7 billion years ago which brought the known universe and everything in it into being.

Despite centuries of increasingly sophisticated observation from planet Earth, only 4 per cent of that universe is known -- because the rest is made up of what have been called, because they are invisible, dark matter and dark energy

Billions of particles flying off from each LHC collision are tracked at four CERN detectors -- and then in collaborating laboratories around the globe -- to establish when and how they come together and what shapes they take.

The CERN theoreticians say this could give clear signs of dimensions beyond length, breadth, depth and time because at such high energy particles could be tracked disappearing -- presumably into them -- and then back into the classical four.

Parallel universes could also be hidden within these dimensions, the thinking goes, but only in a so-called gravitational variety in which light cannot be propagated -- a fact which would make it nearly impossible to explore them.

From: Reuters

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We hope it's not a ginormous trailer park

By: Susie77, 7:32 PM GMT on November 09, 2010

NASA'S FERMI TELESCOPE DISCOVERS GIANT STRUCTURE IN OUR GALAXY

WASHINGTON -- NASA's Fermi Gamma-ray Space Telescope has unveiled a
previously unseen structure centered in the Milky Way. The feature
spans 50,000 light-years and may be the remnant of an eruption from a
supersized black hole at the center of our galaxy.

"What we see are two gamma-ray-emitting bubbles that extend 25,000
light-years north and south of the galactic center," said Doug
Finkbeiner, an astronomer at the Harvard-Smithsonian Center for
Astrophysics in Cambridge, Mass., who first recognized the feature.
"We don't fully understand their nature or origin."

The structure spans more than half of the visible sky, from the
constellation Virgo to the constellation Grus, and it may be millions
of years old. A paper about the findings has been accepted for
publication in The Astrophysical Journal.

Finkbeiner and Harvard graduate students Meng Su and Tracy Slatyer
discovered the bubbles by processing publicly available data from
Fermi's Large Area Telescope (LAT). The LAT is the most sensitive and
highest-resolution gamma-ray detector ever launched. Gamma rays are
the highest-energy form of light.

Other astronomers studying gamma rays hadn't detected the bubbles
partly because of a fog of gamma rays that appears throughout the
sky. The fog happens when particles moving near the speed of light
interact with light and interstellar gas in the Milky Way. The LAT
team constantly refines models to uncover new gamma-ray sources
obscured by this so-called diffuse emission. By using various
estimates of the fog, Finkbeiner and his colleagues were able to
isolate it from the LAT data and unveil the giant bubbles.

Scientists now are conducting more analyses to better understand how
the never-before-seen structure was formed. The bubble emissions are
much more energetic than the gamma-ray fog seen elsewhere in the
Milky Way. The bubbles also appear to have well-defined edges. The
structure's shape and emissions suggest it was formed as a result of
a large and relatively rapid energy release -- the source of which
remains a mystery.

One possibility includes a particle jet from the supermassive black
hole at the galactic center. In many other galaxies, astronomers see
fast particle jets powered by matter falling toward a central black
hole. While there is no evidence the Milky Way's black hole has such
a jet today, it may have in the past. The bubbles also may have
formed as a result of gas outflows from a burst of star formation,
perhaps the one that produced many massive star clusters in the Milky
Way's center several million years ago.

"In other galaxies, we see that starbursts can drive enormous gas
outflows," said David Spergel, a scientist at Princeton University in
New Jersey. "Whatever the energy source behind these huge bubbles may
be, it is connected to many deep questions in astrophysics."

Hints of the bubbles appear in earlier spacecraft data. X-ray
observations from the German-led Roentgen Satellite suggested subtle
evidence for bubble edges close to the galactic center, or in the
same orientation as the Milky Way. NASA's Wilkinson Microwave
Anisotropy Probe detected an excess of radio signals at the position
of the gamma-ray bubbles.

The Fermi LAT team also revealed Tuesday the instrument's best picture
of the gamma-ray sky, the result of two years of data collection.

"Fermi scans the entire sky every three hours, and as the mission
continues and our exposure deepens, we see the extreme universe in
progressively greater detail," said Julie McEnery, Fermi project
scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
NASA's Fermi is an astrophysics and particle physics partnership,
developed in collaboration with the U.S. Department of Energy, with
important contributions from academic institutions and partners in
France, Germany, Italy, Japan, Sweden and the United States.

"Since its launch in June 2008, Fermi repeatedly has proven itself to
be a frontier facility, giving us new insights ranging from the
nature of space-time to the first observations of a gamma-ray nova,"
said Jon Morse, Astrophysics Division director at NASA Headquarters
in Washington. "These latest discoveries continue to demonstrate
Fermi's outstanding performance."

For more information about Fermi, visit:



http://www.nasa.gov/fermi

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Upset by the latest election results?

By: Susie77, 8:16 PM GMT on November 04, 2010

So do something about it! Now you can destroy the Earth and wipe out all those troublesome [Republicans, Tea Partiers, Progressives, Fascists, Nazis, Socialists, Democrats, Commies, Flat-Earthers, Luddites, Creationists, or Cthulites] !

Impact Earth

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Beautiful Comet

By: Susie77, 6:07 PM GMT on November 04, 2010

Comet Hartley 2, taken by Nasa's Deep Impact probe, distance 435 miles:



From Space Weather -- more images

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About Susie77

Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.

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