A New York Time article the morning gives a very cautious report of the results from Sam Ting & company at the AMS, New Clues to the Mystery of Dark Matter:

We still don’t know what’s happening on the dark side of the cosmos, but astronomers said Wednesday that they might be on the verge of finally finding out what makes up the mysterious dark matter that gives shape to the visible structures of the universe.

Saying the results represented evidence of “new physical phenomena,” scientists said Wednesday that a $1.6 billion cosmic ray experiment on the International Space Station had confirmed previous reports that local interstellar space is crackling with an unexplained abundance of high energy particles, especially positrons, the antimatter version of the familiar electrons that constitute electricity and chemistry.

Cosmologists have suggested that decaying dark matter particles would produce such a signal, but so could pulsars, the spinning remnants of dead stars that throw off wild winds of radiation. The disappointing news is that even with the new data, physicists can’t tell yet which is the right answer. “I don’t think it makes you believe it must be dark matter, nor do I think it makes you believe it cannot be,” said Neal Weiner, a particle theorist at New York University.

The good news is that the Alpha Magnetic Spectrometer, as the instrument is called, is only two years into what could be a 10-year voyage on the space station, and is working brilliantly. Samuel Ting, the leader of the spectrometer team, which included scientists from 16 countries, said in a statement released from CERN, “Over the coming months, A.M.S. will be able to tell us conclusively whether these positrons are a signal for dark matter, or whether they have some other origin.”