Space: ISS Alpha Magnetic Spectrometer results delayed
A high-profile dark matter-hunting experiment that sits atop the International Space Station allegedly has interesting results – but its researchers are not telling.
On 17 February, Nobel laureate Samuel Ting of the Massachusetts Institute of Technology, who designed the Alpha Magnetic Spectrometer (AMS), was due to announce the results at the American Association for the Advancement of Science meeting in Boston. But instead he told a disappointed group of reporters and scientists that his team would wait till the work was published in a journal.
AMS launched on the last flight of the space shuttle Endeavour in May 2011, with the goal of catching whiffs of exotic matter. That includes dark matter, which supposedly makes up about 80 per cent of the universe’s matter. According to leading theories, it is made of as-yet-undetected particles called WIMPs, or weakly interacting massive particles.
Electrons and positrons
These WIMPs should collide in space, destroying each other in a puff of electrons and their antimatter partner, positrons. So if AMS picks up more positrons than expected from normal processes, that would suggest the presence of dark matter.
Ting wouldn’t say whether or not AMS has seen such a signal, but did reveal that it has detected 7.7 billion electrons and positrons. That should be enough to suggest, or rule out, a signal at lower energies. “There’s no such thing as disappointing,” said Ting, who plans to submit the work for publication in about two weeks.
Cosmologist Michael Turner of the University of Chicago, who is not on the AMS team, is looking forward to hearing the results. If the device picks up more positrons than expected from normal processes, that would be a “smoking gun signature” of dark matter, he says.
Syndicated content: Lisa Grossman, New Scientist