Potential Dark Matter Discovery a Win for Space Station Science

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.

Read this article:
Potential Dark Matter Discovery a Win for Space Station Science