Daily Archives: April 4, 2013

If nature is kind, the first detection of dark matter might be credited to the International Space Station soon.

Today (April 3), researchers announced the first science results from the Alpha Magnetic Spectrometer (AMS), a $2 billion cosmic-ray particle detector mounted on the exterior of the football-field-size International Space Station. The instrument has observed a striking pattern of antimatter particles called positrons that may turn out to be a product of collisions between dark matter particles.

Though the findings are still uncertain, and the signal could also arise from a more mundane source, the data are, nonetheless, groundbreaking, experts said.

"I think it is fair to say that this is the most important physics result thus far to come from the International Space Station,"theoretical physicist Robert Garisto, who was not involved in the AMS project, wrote today on Twitter. [Photos: See the Alpha Magnetic Spectrometer in Space]

Garisto is editor of the physics journal Physical Review Letters, which published the AMS results in a paper released today.

No matter what the AMS measurements ultimately herald be it dark matter or something else the findings would not have been possible without the platform of the International Space Station, a $100 billion orbiting laboratory staffed full-time by teams of three to six astronauts. AMS collects cosmic-ray particles, which are abundant in space, though largely blocked on Earth by our planet's atmosphere.

In its first 18 months of operations, AMS detected about 30 billion cosmic rays, including 400,000 positrons a haul that allowed significantly more precise statistics than experiments conducted on Earth.

"It's a very major step forward by at least an order of magnitude in sensitivity," Brown University physicist Richard Gaitskell told SPACE.com. Gaitskell is a founding investigator on the Large Underground Xenon experiment, which aims to detect dark-matter particles directly underground in South Dakota.

Dark matter is an invisible substance thought to make up more than 80 percent of the matter in the universe. The elusive stuff is difficult to detect because it very rarely interacts with normal matter, except through its gravitational pull.

One of the leading explanations for dark matter is that it is made up of particles called WIMPs (weakly interacting massive particles), which may produce a detectable signature when they collide and annihilate each other. This happens because WIMPs are thought to be their own antimatter partner particles. When matter and antimatter meet, they destroy each other, so if two WIMPs were to make contact, they would obliterate one another.

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Potential Dark Matter Discovery a Win for Space Station Science

A Hubble Space Telescope image indicating a huge ring of dark matter around the center of the CL0024+17 cluster of galaxies.

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(CNN) -- Nearly two years after it was sent up to the International Space Station, a giant particle physics detector has provided its first results in the search for the mysterious "dark matter" believed to be a major component of the universe.

The international team running the Alpha Magnetic Spectrometer released its initial findings Wednesday at the European Organization for Nuclear Research, known as CERN, in Switzerland.

The scientists are studying flux in cosmic rays, the charged high-energy particles that permeate space, for evidence of the invisible dark matter particles colliding with each other, leading to what is termed "annihilation."

A result of this would be a higher presence of the charged particles known as positrons, the antimatter counterpart of electrons.

According to a CERN statement, the results announced Wednesday "are consistent with the positrons originating from the annihilation of dark matter particles in space, but not yet sufficiently conclusive to rule out other explanations."

How particle smasher and telescopes relate

Over the last few decades, scientists have come to the conclusion that the universe's composition is only about 5% atoms -- in other words, the stuff that we see and know around us. That means the rest is stuff we can't see. About 71% is something called "dark energy," and another 24% is "dark matter."

Research is ongoing to figure out precisely what these "dark" components are, because they do not interact with ordinary matter and have never been directly detected.

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Space station detector gives first clues to 'dark matter'

NASA's first manned outpost in deep space may be a repurposed rocket part, just like the agency's first-ever astronaut abode in Earth orbit.

With a little tinkering, the upper-stage hydrogen propellant tank of NASA's huge Space Launch System rocket would make a nice and relatively cheap deep-space habitat, some researchers say. They call the proposed craft "Skylab II," an homage to the 1970s Skylab space station that was a modified third stage of a Saturn V moon rocket.

"This idea is not challenging technology," said Brand Griffin, an engineer with Gray Research, Inc., who works with the Advanced Concepts Office at NASA's Marshall Space Flight Center in Huntsville, Ala.

"It's just trying to say, 'Is this the time to be able to look at existing assets, planned assets and incorporate those into what we have as a destination of getting humans beyond LEO [low-Earth orbit]?'" Griffin said Wednesday (March 27) during a presentation with NASA's Future In-Space Operations working group. [Gallery: Visions of Deep-Space Stations]

A roomy home in deep space

NASA is developing the Space Launch System (SLS) to launch astronauts toward distant destinations such as near-Earth asteroids and Mars. The rocket's first test flight is slated for 2017, and NASA wants it to start lofting crews by 2021.

The SLS will stand 384 feet tall (117 meters) in its biggest ("evolved") incarnation, which will be capable of blasting 130 metric tons of payload to orbit. Its upper-stage hydrogen tank is big, too, measuring 36.1 feet tall by 27.6 feet wide (11.15 m by 8.5 m).

The tank's dimensions yield an internal volume of 17,481 cubic feet (495 cubic m) roughly equivalent to a two-story house. That's much roomier than a potential deep-space habitat derived from modules of the International Space Station (ISS), which are just 14.8 feet (4.5 m) wide, Griffin said.

The tank-based Skylab II could accommodate a crew of four comfortably and carry enough gear and food to last for several years at a time without requiring a resupply, he added. Further, it would launch aboard the SLS in a single piece, whereas ISS-derived habitatswould need to link up multiple components in space.

Because of this, SkylabII would require relatively few launches to establish and maintain, Griffin said. That and the use of existing SLS-manufacturing infrastructure would translate into big cost savings a key selling point in today's tough fiscal climate.

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NASA Mega-Rocket Could Lead to Skylab 2 Deep Space Station

Astronauts work to install the alpha magnetic spectrometer on the International Space Station on May 26, 2011.

Astronauts work to install the alpha magnetic spectrometer on the International Space Station on May 26, 2011.

An international team of researchers announced in Switzerland on Wednesday that an experiment on the International Space Station may have seen hints of something called dark matter. The finding could be a milestone in the decades-long search for the universe's missing material.

Only a tiny sliver of stuff in the universe is visible to scientists; the rest is dark matter. Researchers don't know what it is, but they know it's there. Its gravity pulls on the things we can see.

"We live in a sea of dark matter. Our galaxy is embedded in a huge roughly spherical halo of dark matter particles," says Michael Salamon, who is with the U.S. Department of Energy.

Salamon, who was part of the team behind Wednesday's announcement, says that dark matter is beyond anything predicted by current scientific theories.

"What that means is, if we detect dark matter and learn something about its nature, we will have made a major impact to our understanding of physics and nature itself," he says.

That's a big part of why scientists from 16 countries spent $2 billion building a detector designed to pick up any hint of this mystery material. Their Alpha Magnetic Spectrometer was carried into space two years ago and bolted onto the side of the International Space Station.

Researchers announced Wednesday the AMS has detected a large number of high-energy particles, which could be coming from collisions of dark matter. Theories suggest that when dark matter particles smash together, they annihilate one another. The enormous energy released creates visible particles, and it's these particles that might be showing up in the detector.

Sam Ting, a Nobel Prize-winning physicist who is responsible for the AMS, says this is only the beginning. As the AMS collects more particles, it should be able to tell whether they are coming from dark matter collisions.

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Sensor On Space Station May Have Seen Hints Of Elusive Dark Matter