In May of 2011, after over a decade of work by scientists from 16 different countries, the Alpha Magnetic Spectrometer (AMS) was installed at the International Space Station. The project cost well over $2 billion dollars, and last-minute funding from Congress was needed to complete the installation.
Almost two years later, all of that time and money is beginning to pay off.
On Wednesday, researchers announced that they may have found tangible evidence of dark matter in space. For years, scientists have assumed the existence of dark matter, but until the AMS, no detection equipment was sophisticated enough to provide evidence for these assumptions.
The Alpha Magnetic Spectrometer was designed to collect data from cosmic rays, and then sort through this data for a specific particle that could only be created if two dark matter particles collided and destroyed each other. On Wednesday, scientists announced that the AMS has detected over 400,000 of these particles, called positrons.
“Our evidence supports the evidence of dark matter,” lead AMS researcher Samuel Ting said. Ting added that the evidence is not conclusive at this time, saying the positrons could possibly have been emitted by pulsar stars as well. However, Ting believes that with time, the AMS will provide data that allows scientists to discover the true origin of positrons.
“I’m confident with enough time we’ll solve this problem,” he said. “Over the coming months, AMS will be able to tell us conclusively whether these positrons are a signal for dark matter, or whether they have some other origin,” Ting added.
In order to determine the origin of positrons, researchers will use AMS data to see how many positrons are emitted at high cosmic energy levels. If dark matter hypothesis are correct, researchers should see a sharp drop in positron emissions at energy levels over 250 billion electron volts.
"We want to know how quickly it drops off, how sharp is the drop-off," Ting said. "It's the way it drops off that tells you whether it's dark matter collisions, or from pulsars."
Ting said the level of detail found in the AMS data is unlike anything science has seen before, comparing it to the difference between seeing something with a naked eye versus a microscope. “It is these fine features that are the difference between us and the other experiments,” he said.
Although the scientific jargon of positrons and electron volts can be tough to digest, the message to take away from this research is that a major piece of the modern physics puzzle will likely be solved soon. The AMS data holds answers that scientists have been pursuing for decades.
NASA administrator Charles Bolden issued a statement on Wednesday reiterating how groundbreaking the AMS’ findings are.
“I am confident that this is only the first of many scientific discoveries enabled by the station that will change our understanding of the universe," he said.